bpo-37415: Fix stdatomic.h header check for ICC compiler (GH-16717)

Fix stdatomic.h header check for ICC compiler: the ICC implementation
lacks atomic_uintptr_t type which is needed by Python.

Test:

* atomic_int and atomic_uintptr_t types
* atomic_load_explicit() and atomic_store_explicit()
* memory_order_relaxed and memory_order_seq_cst constants

But don't test ATOMIC_VAR_INIT(): it's not used in Python.

Misc/NEWS.d/next/Build/2019-10-11-15-32-58.bpo-37415.D9RXrq.rst

+Fix stdatomic.h header check for ICC compiler: the ICC implementation lacks
+atomic_uintptr_t type which is needed by Python.

configure

@@ -782,7 +782,6 @@ infodir
 docdir
 oldincludedir
 includedir
-runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -896,7 +895,6 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
-runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1149,15 +1147,6 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
 
-  -runstatedir | --runstatedir | --runstatedi | --runstated \
-  | --runstate | --runstat | --runsta | --runst | --runs \
-  | --run | --ru | --r)
-    ac_prev=runstatedir ;;
-  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
-  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
-  | --run=* | --ru=* | --r=*)
-    runstatedir=$ac_optarg ;;
-
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1295,7 +1284,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir runstatedir
+		libdir localedir mandir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -1448,7 +1437,6 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
-  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -16775,9 +16763,12 @@ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 
 
     #include <stdatomic.h>
-    atomic_int value = ATOMIC_VAR_INIT(1);
+    atomic_int int_var;
+    atomic_uintptr_t uintptr_var;
     int main() {
-      int loaded_value = atomic_load(&value);
+      atomic_store_explicit(&int_var, 5, memory_order_relaxed);
+      atomic_store_explicit(&uintptr_var, 0, memory_order_relaxed);
+      int loaded_value = atomic_load_explicit(&int_var, memory_order_seq_cst);
       return 0;
     }
 

configure.ac

@@ -5414,9 +5414,12 @@ AC_LINK_IFELSE(
 [
   AC_LANG_SOURCE([[
     #include <stdatomic.h>
-    atomic_int value = ATOMIC_VAR_INIT(1);
+    atomic_int int_var;
+    atomic_uintptr_t uintptr_var;
     int main() {
-      int loaded_value = atomic_load(&value);
+      atomic_store_explicit(&int_var, 5, memory_order_relaxed);
+      atomic_store_explicit(&uintptr_var, 0, memory_order_relaxed);
+      int loaded_value = atomic_load_explicit(&int_var, memory_order_seq_cst);
       return 0;
     }
   ]])
@@ -5426,7 +5429,7 @@ AC_MSG_RESULT($have_stdatomic_h)
 
 if test "$have_stdatomic_h" = yes; then
     AC_DEFINE(HAVE_STD_ATOMIC, 1,
-              [Has stdatomic.h with atomic_int])
+              [Has stdatomic.h with atomic_int and atomic_uintptr_t])
 fi
 
 # Check for GCC >= 4.7 __atomic builtins

pyconfig.h.in

@@ -1018,7 +1018,7 @@
 /* Define to 1 if you have the <stdlib.h> header file. */
 #undef HAVE_STDLIB_H
 
-/* Has stdatomic.h with atomic_int */
+/* Has stdatomic.h with atomic_int and atomic_uintptr_t */
 #undef HAVE_STD_ATOMIC
 
 /* Define to 1 if you have the `strdup' function. */