Remove unreachable code in Clang. (replace with llvm_unreachable where appropriate or when GCC requires it)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148292 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index af0eedd..e94aa2f 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -342,7 +342,7 @@
     assert(!shift && "cannot shift float types!");
     return (2 << IsQuad) - 1;
   }
-  return 0;
+  llvm_unreachable("Invalid NeonTypeFlag!");
 }
 
 /// getNeonEltType - Return the QualType corresponding to the elements of
@@ -367,7 +367,7 @@
   case NeonTypeFlags::Float32:
     return Context.FloatTy;
   }
-  return QualType();
+  llvm_unreachable("Invalid NeonTypeFlag!");
 }
 
 bool Sema::CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {