cppmacro.c (STDC_0_IN_SYSTEM_HEADERS): Define to 0 if undefined.

	* cppmacro.c (STDC_0_IN_SYSTEM_HEADERS): Define to 0 if
	undefined.  Remove #ifdef check.
	* config/i386/sol2.h, config/rs6000/sol2.h, config/sparc/sol2.h:
	Define STDC_0_IN_SYSTEM_HEADERS to 1.

From-SVN: r37163

gcc/config/i386/sol2.h

@@ -127,7 +127,7 @@ Boston, MA 02111-1307, USA.  */
    || (CHAR) == 'h' \
    || (CHAR) == 'z')
 
-#define STDC_0_IN_SYSTEM_HEADERS
+#define STDC_0_IN_SYSTEM_HEADERS 1
 
 #undef LOCAL_LABEL_PREFIX
 #define LOCAL_LABEL_PREFIX "."

gcc/config/rs6000/sol2.h

@@ -171,4 +171,4 @@ while (0)
 #undef	MULTILIB_DEFAULTS
 #define	MULTILIB_DEFAULTS { "mlittle", "mcall-solaris" }
 
-#define STDC_0_IN_SYSTEM_HEADERS
+#define STDC_0_IN_SYSTEM_HEADERS 1

gcc/config/sparc/sol2.h

@@ -185,7 +185,7 @@ Boston, MA 02111-1307, USA.  */
 /* But indicate that it isn't supported by the hardware.  */
 #define WIDEST_HARDWARE_FP_SIZE 64
 
-#define STDC_0_IN_SYSTEM_HEADERS
+#define STDC_0_IN_SYSTEM_HEADERS 1
 
 #define MULDI3_LIBCALL "__mul64"
 #define DIVDI3_LIBCALL "__div64"

gcc/cppmacro.c

@@ -29,6 +29,10 @@ Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #include "cpplib.h"
 #include "cpphash.h"
 
+#ifndef STDC_0_IN_SYSTEM_HEADERS
+#define STDC_0_IN_SYSTEM_HEADERS 0 /* Boolean macro.  */
+#endif
+
 struct cpp_macro
 {
   cpp_hashnode **params;	/* Parameters, if any.  */
@@ -189,11 +193,9 @@ builtin_macro (pfile, token)
       {
 	int stdc = 1;
 
-#ifdef STDC_0_IN_SYSTEM_HEADERS
-	if (CPP_IN_SYSTEM_HEADER (pfile)
+	if (STDC_0_IN_SYSTEM_HEADERS && CPP_IN_SYSTEM_HEADER (pfile)
 	    && pfile->spec_nodes.n__STRICT_ANSI__->type == NT_VOID)
 	  stdc = 0;
-#endif
 	make_number_token (pfile, token, stdc);
       }
       break;