Address review feedback by adding comments about ${:uid}

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@288868 91177308-0d34-0410-b5e6-96231b3b80d8

Author: rnk

lib/Sema/SemaStmtAsm.cpp

@@ -750,9 +750,11 @@ LabelDecl *Sema::GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
     // Otherwise, insert it, but only resolve it if we have seen the label itself.
     std::string InternalName;
     llvm::raw_string_ostream OS(InternalName);
-    // Create an internal name for the label.  The name should not be a valid mangled
-    // name, and should be unique.  We use a dot to make the name an invalid mangled
-    // name.
+    // Create an internal name for the label.  The name should not be a valid
+    // mangled name, and should be unique.  We use a dot to make the name an
+    // invalid mangled name. We use LLVM's inline asm ${:uid} escape so that a
+    // unique label is generated each time this blob is emitted, even after
+    // inlining or LTO.
     OS << "__MSASMLABEL_.${:uid}__";
     for (char C : ExternalLabelName) {
       OS << C;