Port to PGI 16.10 x86-64

This patch fixes one real bug in gl_anylinked_list2.h, along with some minor
glitches that are not bugs. It does not silence PGI's thousands of bogus
warnings when compiling test-intprops.c. Fortunately, the warnings do not
cause a failure.

* lib/c-ctype.h (_C_CTYPE_LOWER_A_THRU_F_N, _C_CTYPE_LOWER_N): Rename parameter
  to avoid PGI warning about '#define f(n) 'n''. My goodness, PGI goes back a
  long ways - this predates C89!
* lib/gl_anylinked_list2.h (ASYNCSAFE): Fix bug caught by PGI. For example,
  ASYNCSAFE (const void *) should expand to 'const void *volatile', not to
  'volatile const void *'.
* lib/spawn.in.h (POSIX_SPAWN_USEVFORK): Don't define if already defined.
* lib/verify.h (verify) [!__GNUC__]: Use shorter albeit meaningless string to
  bypass silly compiler limits.
* tests/infinity.h (Infinityf, Infinityd, Infinityl) [__PGI]:
* tests/nan.h (NaNf, NaNd, NaNl): Use static functions to avoid misguided
  compiler diagnostics. Is there some reason we don’t use static functions
  on all platforms?

diff --git a/lib/c-ctype.h b/lib/c-ctype.h
index bdca1f1..ec6a3a0 100644
--- a/lib/c-ctype.h
+++ b/lib/c-ctype.h
@@ -115,16 +115,16 @@ extern "C" {
 
 /* Cases for lowercase hex letters, and lowercase letters, all offset by N.  */
 
-#define _C_CTYPE_LOWER_A_THRU_F_N(n) \
-   case 'a' + (n): case 'b' + (n): case 'c' + (n): case 'd' + (n): \
-   case 'e' + (n): case 'f' + (n)
-#define _C_CTYPE_LOWER_N(n) \
-   _C_CTYPE_LOWER_A_THRU_F_N(n): \
-   case 'g' + (n): case 'h' + (n): case 'i' + (n): case 'j' + (n): \
-   case 'k' + (n): case 'l' + (n): case 'm' + (n): case 'n' + (n): \
-   case 'o' + (n): case 'p' + (n): case 'q' + (n): case 'r' + (n): \
-   case 's' + (n): case 't' + (n): case 'u' + (n): case 'v' + (n): \
-   case 'w' + (n): case 'x' + (n): case 'y' + (n): case 'z' + (n)
+#define _C_CTYPE_LOWER_A_THRU_F_N(N) \
+   case 'a' + (N): case 'b' + (N): case 'c' + (N): case 'd' + (N): \
+   case 'e' + (N): case 'f' + (N)
+#define _C_CTYPE_LOWER_N(N) \
+   _C_CTYPE_LOWER_A_THRU_F_N(N): \
+   case 'g' + (N): case 'h' + (N): case 'i' + (N): case 'j' + (N): \
+   case 'k' + (N): case 'l' + (N): case 'm' + (N): case 'n' + (N): \
+   case 'o' + (N): case 'p' + (N): case 'q' + (N): case 'r' + (N): \
+   case 's' + (N): case 't' + (N): case 'u' + (N): case 'v' + (N): \
+   case 'w' + (N): case 'x' + (N): case 'y' + (N): case 'z' + (N)
 
 /* Cases for hex letters, digits, lower, punct, and upper.  */
 
diff --git a/lib/gl_anylinked_list2.h b/lib/gl_anylinked_list2.h
index c249f31..4545da9 100644
--- a/lib/gl_anylinked_list2.h
+++ b/lib/gl_anylinked_list2.h
@@ -29,7 +29,7 @@
    and we use 'volatile' assignments to prevent the compiler from reordering
    such assignments.  */
 #ifdef SIGNAL_SAFE_LIST
-# define ASYNCSAFE(type) *(volatile type *)&
+# define ASYNCSAFE(type) *(type volatile *)&
 #else
 # define ASYNCSAFE(type)
 #endif
diff --git a/lib/spawn.in.h b/lib/spawn.in.h
index e8116f9..b4b9197 100644
--- a/lib/spawn.in.h
+++ b/lib/spawn.in.h
@@ -142,7 +142,8 @@ typedef struct
 # endif
 #endif
 /* A GNU extension.  Use the next free bit position.  */
-#define POSIX_SPAWN_USEVFORK \
+#ifndef POSIX_SPAWN_USEVFORK
+# define POSIX_SPAWN_USEVFORK \
   ((POSIX_SPAWN_RESETIDS | (POSIX_SPAWN_RESETIDS - 1)                     \
     | POSIX_SPAWN_SETPGROUP | (POSIX_SPAWN_SETPGROUP - 1)                 \
     | POSIX_SPAWN_SETSIGDEF | (POSIX_SPAWN_SETSIGDEF - 1)                 \
@@ -152,6 +153,7 @@ typedef struct
     | POSIX_SPAWN_SETSCHEDULER                                            \
     | (POSIX_SPAWN_SETSCHEDULER > 0 ? POSIX_SPAWN_SETSCHEDULER - 1 : 0))  \
    + 1)
+#endif
 #if !GNULIB_defined_verify_POSIX_SPAWN_USEVFORK_no_overlap
 typedef int verify_POSIX_SPAWN_USEVFORK_no_overlap
             [(((POSIX_SPAWN_RESETIDS | POSIX_SPAWN_SETPGROUP
diff --git a/lib/verify.h b/lib/verify.h
index dcaf7ca..dcba9c8 100644
--- a/lib/verify.h
+++ b/lib/verify.h
@@ -248,7 +248,12 @@ template <int w>
 /* Verify requirement R at compile-time, as a declaration without a
    trailing ';'.  */
 
-#define verify(R) _GL_VERIFY (R, "verify (" #R ")")
+#ifdef __GNUC__
+# define verify(R) _GL_VERIFY (R, "verify (" #R ")")
+#else
+/* PGI barfs if R is long.  Play it safe.  */
+# define verify(R) _GL_VERIFY (R, "verify (...)")
+#endif
 
 #ifndef __has_builtin
 # define __has_builtin(x) 0
diff --git a/tests/infinity.h b/tests/infinity.h
index 431f700..ef5d3bd 100644
--- a/tests/infinity.h
+++ b/tests/infinity.h
@@ -18,8 +18,9 @@
 /* Infinityf () returns a 'float' +Infinity.  */
 
 /* The Microsoft MSVC 9 compiler chokes on the expression 1.0f / 0.0f.
-   The IBM XL C compiler on z/OS complains.  */
-#if defined _MSC_VER || (defined __MVS__ && defined __IBMC__)
+   The IBM XL C compiler on z/OS complains.
+   PGI 16.10 complains.  */
+#if defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI
 static float
 Infinityf ()
 {
@@ -34,8 +35,9 @@ Infinityf ()
 /* Infinityd () returns a 'double' +Infinity.  */
 
 /* The Microsoft MSVC 9 compiler chokes on the expression 1.0 / 0.0.
-   The IBM XL C compiler on z/OS complains.  */
-#if defined _MSC_VER || (defined __MVS__ && defined __IBMC__)
+   The IBM XL C compiler on z/OS complains.
+   PGI 16.10 complains.  */
+#if defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI
 static double
 Infinityd ()
 {
@@ -50,8 +52,9 @@ Infinityd ()
 /* Infinityl () returns a 'long double' +Infinity.  */
 
 /* The Microsoft MSVC 9 compiler chokes on the expression 1.0L / 0.0L.
-   The IBM XL C compiler on z/OS complains.  */
-#if defined _MSC_VER || (defined __MVS__ && defined __IBMC__)
+   The IBM XL C compiler on z/OS complains.
+   PGI 16.10 complains.  */
+#if defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI
 static long double
 Infinityl ()
 {
diff --git a/tests/nan.h b/tests/nan.h
index 48236b5..b5a0f29 100644
--- a/tests/nan.h
+++ b/tests/nan.h
@@ -25,8 +25,11 @@
 /* NaNf () returns a 'float' not-a-number.  */
 
 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
-   on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.  */
-#if defined __DECC || defined _MSC_VER || (defined __MVS__ && defined __IBMC__)
+   on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.
+   PGI 16.10 complains.  */
+#if (defined __DECC || defined _MSC_VER \
+     || (defined __MVS__ && defined __IBMC__)   \
+     || defined __PGI)
 static float
 NaNf ()
 {
@@ -41,8 +44,11 @@ NaNf ()
 /* NaNd () returns a 'double' not-a-number.  */
 
 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
-   on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.  */
-#if defined __DECC || defined _MSC_VER || (defined __MVS__ && defined __IBMC__)
+   on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.
+   PGI 16.10 complains.  */
+#if (defined __DECC || defined _MSC_VER \
+     || (defined __MVS__ && defined __IBMC__)   \
+     || defined __PGI)
 static double
 NaNd ()
 {
@@ -59,14 +65,15 @@ NaNd ()
 /* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the
    runtime type conversion.
    The Microsoft MSVC 9 compiler chokes on the expression 0.0L / 0.0L.
-   The IBM XL C compiler on z/OS complains.  */
+   The IBM XL C compiler on z/OS complains.
+   PGI 16.10 complains.  */
 #ifdef __sgi
 static long double NaNl ()
 {
   double zero = 0.0;
   return zero / zero;
 }
-#elif defined _MSC_VER || (defined __MVS__ && defined __IBMC__)
+#elif defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI
 static long double
 NaNl ()
 {