Just disable the compiler-builtins module test on MSVC for now

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149214 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Modules/compiler_builtins.m b/test/Modules/compiler_builtins.m
index 3545604..38ce2c9 100644
--- a/test/Modules/compiler_builtins.m
+++ b/test/Modules/compiler_builtins.m
@@ -1,6 +1,9 @@
 // RUN: rm -rf %t
 // RUN: %clang -fsyntax-only -fmodules -fmodule-cache-path %t %s -Xclang -verify
 
+// Note: disable test on MSVC, which doesn't have <complex.h>.
+// REQUIRES: shell
+
 @import __compiler_builtins.float_constants;
 
 float getFltMax() { return FLT_MAX; }