[llvm] [clang] [AIX][TOC] Add -mtocdata/-mno-tocdata options on AIX (PR #67999)

[via cfe-commits]

================
@@ -429,13 +429,101 @@ void AIX::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,
   llvm_unreachable("Unexpected C++ library type; only libc++ is supported.");
 }
 
+// This function processes all the mtocdata options to build the final
+// simplified toc data options to pass to CC1.
+static void addTocDataOptions(const llvm::opt::ArgList &Args,
+                              llvm::opt::ArgStringList &CC1Args,
+                              const Driver &D) {
+
+  // Check the global toc-data setting. The default is -mno-tocdata.
+  // To enable toc-data globally, -mtocdata must be specified.
+  // Additionally, it must be last to take effect.
+  const bool TOCDataGloballyinEffect = [&Args]() {
+    if (!Args.hasArg(options::OPT_mtocdata))
+      return false;
+
+    const Arg *LastArg =
+        Args.getLastArg(options::OPT_mtocdata, options::OPT_mno_tocdata);
+    return LastArg->getOption().matches(options::OPT_mtocdata);
+  }();
----------------
diggerlin wrote:

since 
```
bool hasArg(OptSpecifiers ...Ids) const {
    return getLastArg(Ids...) != nullptr;
  } |
```
we can change 

```
if (!Args.hasArg(options::OPT_mtocdata))
      return false;

    const Arg *LastArg =
        Args.getLastArg(options::OPT_mtocdata, options::OPT_mno_tocdata);
    return LastArg->getOption().matches(options::OPT_mtocdata);
```
to

```
    if(const Arg *LastArg = Args.getLastArg(options::OPT_mtocdata, options::OPT_mno_tocdata))
         return LastArg->getOption().matches(options::OPT_mtocdata);
      else 
         return false;
```

https://github.com/llvm/llvm-project/pull/67999