pythonGH-131296: Suppress "unused label" warning for clang-cl closer to actual occurrence (pythonGH-131900)

Author: chris-eibl

PCbuild/pyproject-clangcl.props

@@ -46,7 +46,7 @@
       Please see GH-131691 for details.
       -->
       <ExceptionHandling>Async</ExceptionHandling>
-      <AdditionalOptions>-Wno-deprecated-non-prototype -Wno-unused-label -Wno-pointer-sign -Wno-incompatible-pointer-types-discards-qualifiers -Wno-unused-function %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions>-Wno-pointer-sign -Wno-incompatible-pointer-types-discards-qualifiers -Wno-unused-function %(AdditionalOptions)</AdditionalOptions>
       <AdditionalOptions Condition="'$(Platform)' == 'Win32'">-m32 %(AdditionalOptions)</AdditionalOptions>
       <AdditionalOptions Condition="'$(Platform)' == 'x64'">-m64 %(AdditionalOptions)</AdditionalOptions>
       <AdditionalOptions Condition="$(Configuration) != 'Debug'">-flto=thin %(AdditionalOptions)</AdditionalOptions>

Python/ceval.c

@@ -891,7 +891,7 @@ extern void _PyUOpPrint(const _PyUOpInstruction *uop);
    if computed gotos aren't used. */
 
 /* TBD - what about other compilers? */
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__clang__)
 #  pragma GCC diagnostic push
 #  pragma GCC diagnostic ignored "-Wunused-label"
 #elif defined(_MSC_VER) /* MS_WINDOWS */
@@ -1179,7 +1179,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
 #  pragma optimize("", on)
 #endif
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__clang__)
 #  pragma GCC diagnostic pop
 #elif defined(_MSC_VER) /* MS_WINDOWS */
 #  pragma warning(pop)