[clang] [Clang] Fix stmtexprs.c to explicitly require -std=c11 (PR #226161)

[ahmed mohamed kamel via cfe-commits]

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@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -Wno-gnu-statement-expression
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only -std=c11 -Wno-gnu-statement-expression
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AhmedKamel10 wrote:

Makes sense. `-pedantic` predates my changes. Since everything here is intentionally testing GNU extensions, agreed it can be removed.l update the RUN line to:
`// RUN: %clang_cc1 %s -verify -fsyntax-only`. 

https://github.com/llvm/llvm-project/pull/226161