Update build-tools to ab/5149936

Test: treehugger
Change-Id: I01ef136c306ba814c979ac93e654644112291613
diff --git a/common/bison/lalr1.cc b/common/bison/lalr1.cc
index c6e1977..06f0ded 100644
--- a/common/bison/lalr1.cc
+++ b/common/bison/lalr1.cc
@@ -376,9 +376,7 @@
               if (*++yyp != '\\')
                 goto do_not_strip_quotes;
               /* Fall through.  */
-#if defined(__has_cpp_attribute) && __has_cpp_attribute(clang::fallthrough)
-              [[clang::fallthrough]];
-#endif
+              [[fallthrough]];
             default:
               yyr += *yyp;
               break;