[clang] [clang][modules] Print library module manifest path. (PR #76451)

[Chuanqi Xu via cfe-commits]

================
@@ -6135,6 +6141,42 @@ std::string Driver::GetProgramPath(StringRef Name, const ToolChain &TC) const {
   return std::string(Name);
 }
 
+std::string Driver::GetStdModuleManifestPath(const Compilation &C,
+                                             const ToolChain &TC) const {
+
+  std::string error = "<NOT PRESENT>";
+
+  switch (TC.GetCXXStdlibType(C.getArgs())) {
+  case ToolChain::CST_Libcxx: {
+    std::string lib = "libc++.so";
+    std::string path = GetFilePath(lib, TC);
+
+    // Note when there are multiple flavours of libc++ the module json needs to
+    // look at the command-line arguments for the proper json.
----------------
ChuanqiXu9 wrote:

As a people who don't super know libc++, it is confusing to understand `multiple flavous of libc++`, so if necessary, let's try to add a link here.

https://github.com/llvm/llvm-project/pull/76451