[clang] [X86] Update BMI, BMI2 and TBM constexpr tests (PR #156260)

[Simon Pilgrim via cfe-commits]

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@@ -237,85 +238,85 @@ unsigned long long test_blsr_u64(unsigned long long __X) {
 
 // Test constexpr handling.
 #if defined(__cplusplus) && (__cplusplus >= 201103L)
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RKSimon wrote:

now unnecessary - TEST_CONSTEXPR should handle it

https://github.com/llvm/llvm-project/pull/156260