Added LLVM_FALLTHROUGH to address warning: this statement may fall through. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@304472 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Parse/ParseDecl.cpp

@@ -2552,6 +2552,7 @@ bool Parser::ParseImplicitInt(DeclSpec &DS, CXXScopeSpec *SS,
         }
       }
       // Fall through.
+      LLVM_FALLTHROUGH;
     }
     case tok::comma:
     case tok::equal:
@@ -3678,6 +3679,7 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
         isInvalid = true;
         break;
       };
+      LLVM_FALLTHROUGH;
     case tok::kw___private:
     case tok::kw___global:
     case tok::kw___local:
@@ -5045,6 +5047,7 @@ void Parser::ParseTypeQualifierListOpt(
         if (TryKeywordIdentFallback(false))
           continue;
       }
+      LLVM_FALLTHROUGH;
     case tok::kw___sptr:
     case tok::kw___w64:
     case tok::kw___ptr64:
@@ -5094,6 +5097,7 @@ void Parser::ParseTypeQualifierListOpt(
         continue; // do *not* consume the next token!
       }
       // otherwise, FALL THROUGH!
+      LLVM_FALLTHROUGH;
     default:
       DoneWithTypeQuals:
       // If this is not a type-qualifier token, we're done reading type