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

[Aaron Ballman 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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AaronBallman wrote:

Instead of pinning to C11, I think it may be better to drop `-pedantic -Wno-gnu-statement-expression`; the diagnostics are all related to `-pedantic` being enabled but I don't see a reason for that to be enabled in the first place.

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