[clang] [Clang] Add -fwrapv-pointer flag (PR #122486)

[Fangrui Song via cfe-commits]

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@@ -1,11 +1,20 @@
 // RUN: %clang -### -S -fwrapv -fno-wrapv -fwrapv %s 2>&1 | FileCheck -check-prefix=CHECK1 %s
 // CHECK1: -fwrapv
 //
+// RUN: %clang -### -S -fwrapv-pointer -fno-wrapv-pointer -fwrapv-pointer %s 2>&1 | FileCheck -check-prefix=CHECK1-POINTER %s
+// CHECK1-POINTER: -fwrapv-pointer
+//
 // RUN: %clang -### -S -fstrict-overflow -fno-strict-overflow %s 2>&1 | FileCheck -check-prefix=CHECK2 %s
-// CHECK2: -fwrapv
+// CHECK2: -fwrapv{{.*}}-fwrapv-pointer
 //
-// RUN: %clang -### -S -fwrapv -fstrict-overflow %s 2>&1 | FileCheck -check-prefix=CHECK3 %s
+// RUN: %clang -### -S -fwrapv -fstrict-overflow %s 2>&1 | FileCheck -check-prefix=CHECK3 %s --implicit-check-not="-fwrapv-pointer"
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MaskRay wrote:

When testing both -fno-strict-overflow and -fwrapv{-pointer}, perhaps add -Werror to ensure that we don't emit a unused option warning (which would happen if the Driver code forgot to claim an option).

https://github.com/llvm/llvm-project/pull/122486