[llvm] [clang] [SystemZ][z/OS] This change adds support for the PPA2 section in zOS (PR #68926)

[Ulrich Weigand via llvm-commits]

================
@@ -1026,6 +1030,78 @@ void SystemZAsmPrinter::emitADASection() {
   OutStreamer->popSection();
 }
 
+static uint32_t getProductVersion(Module &M) {
+  if (auto *VersionVal = cast_or_null<ConstantAsMetadata>(
+          M.getModuleFlag("zos_product_major_version")))
+    return cast<ConstantInt>(VersionVal->getValue())->getZExtValue();
----------------
uweigand wrote:

I think instead of these two casts, these days you're supposed to use the new `mdconst` interface, e.g. like
```
if (auto *VersionVal = mdconst::extract_or_null<ConstantInt>(
        M.getModuleFlag("zos_product_major_version"))
```


https://github.com/llvm/llvm-project/pull/68926