Change default C dialect for PS5 to gnu17/gnu18.

Differential Revision: https://reviews.llvm.org/D129404

clang/lib/Basic/LangStandards.cpp

@@ -61,8 +61,8 @@ LangStandard::Kind clang::getDefaultLanguageStandard(clang::Language Lang,
     if (CLANG_DEFAULT_STD_C != LangStandard::lang_unspecified)
       return CLANG_DEFAULT_STD_C;
 
-    // The PS4 and PS5 use C99 as the default C standard.
-    if (T.isPS())
+    // The PS4 uses C99 as the default C standard.
+    if (T.isPS4())
       return LangStandard::lang_gnu99;
     return LangStandard::lang_gnu17;
   case Language::ObjC:

clang/test/Preprocessor/init.c

@@ -1342,7 +1342,8 @@
 // PS4:#define __SSE2__ 1
 // PS4:#define __SSE_MATH__ 1
 // PS4:#define __SSE__ 1
-// PS4:#define __STDC_VERSION__ 199901L
+// PS4ONLY:#define __STDC_VERSION__ 199901L
+// PS5ONLY:#define __STDC_VERSION__ 201710L
 // PS4:#define __UINTMAX_TYPE__ long unsigned int
 // PS4:#define __USER_LABEL_PREFIX__
 // PS4:#define __WCHAR_MAX__ 65535