Fix bogus MSVC char8_t mangling.

This appears to have been caused by a bad automatic svn merge with r330225
attaching the 'case' label to the wrong block of code. :(

llvm-svn: 331299
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index f39c1a8..7b60c14 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -1918,7 +1918,6 @@
     Out << "$$T";
     break;
 
-  case BuiltinType::Char8:
   case BuiltinType::Float16:
     mangleArtificalTagType(TTK_Struct, "_Float16", {"__clang"});
     break;
@@ -1927,6 +1926,7 @@
     mangleArtificalTagType(TTK_Struct, "_Half", {"__clang"});
     break;
 
+  case BuiltinType::Char8:
   case BuiltinType::Float128: {
     DiagnosticsEngine &Diags = Context.getDiags();
     unsigned DiagID = Diags.getCustomDiagID(