[libcxxabi] r345870 - Use C++11 fallthrough attribute syntax when available and add a break

[Reid Kleckner]

Author: rnk
Date: Thu Nov  1 11:24:03 2018
New Revision: 345870

URL: http://llvm.org/viewvc/llvm-project?rev=345870&view=rev
Log:
Use C++11 fallthrough attribute syntax when available and add a break

Summary:
This silences the two -Wimplicit-fallthrough warnings clang finds in
ItaniumDemangle.h in libc++abi.

Clang does not have a GNU attribute spelling for this attribute, so this
is necessary.

I will commit the same change to the LLVM demangler soon.

Reviewers: EricWF, ldionne

Subscribers: christof, erik.pilkington, cfe-commits

Differential Revision: https://reviews.llvm.org/D53985

Modified:
    libcxxabi/trunk/src/demangle/ItaniumDemangle.h

Modified: libcxxabi/trunk/src/demangle/ItaniumDemangle.h
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/demangle/ItaniumDemangle.h?rev=345870&r1=345869&r2=345870&view=diff
==============================================================================
--- libcxxabi/trunk/src/demangle/ItaniumDemangle.h (original)
+++ libcxxabi/trunk/src/demangle/ItaniumDemangle.h Thu Nov  1 11:24:03 2018
@@ -2812,6 +2812,7 @@ AbstractManglingParser<Derived, Alloc>::
       SoFar = make<ExpandedSpecialSubstitution>(SSK);
       if (!SoFar)
         return nullptr;
+      break;
     default:
       break;
     }