[clang] [Clang] Add __builtin_bswapg (PR #162433)

[Oliver Hunt via cfe-commits]

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@@ -0,0 +1,212 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -verify -fexperimental-new-constant-interpreter %s
+
+void test_basic_type_checks() {
+  static_assert(__is_same(char, decltype(__builtin_bswapg((char)0))), "");
+  static_assert(__is_same(unsigned char, decltype(__builtin_bswapg((unsigned char)0))), "");
+  static_assert(__is_same(short, decltype(__builtin_bswapg((short)0))), "");
+  static_assert(__is_same(unsigned short, decltype(__builtin_bswapg((unsigned short)0))), "");
+  static_assert(__is_same(int, decltype(__builtin_bswapg((int)0))), "");
+  static_assert(__is_same(unsigned int, decltype(__builtin_bswapg((unsigned int)0))), "");
+  static_assert(__is_same(long, decltype(__builtin_bswapg((long)0))), "");
+  static_assert(__is_same(unsigned long, decltype(__builtin_bswapg((unsigned long)0))), "");
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ojhunt wrote:

Can you add the same for _BitInt types?

https://github.com/llvm/llvm-project/pull/162433