Revert r288787: Add missing stdbool.h module.

Reverting because I didn't properly test this patch. Although it's probably
correct to add a stdbool_h module I thought the change fixed more than it did.
I'll re-commit after more investigation.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@288789 91177308-0d34-0410-b5e6-96231b3b80d8

include/module.modulemap

@@ -40,10 +40,7 @@ module std [system] {
     // FIXME: <stdalign.h> is missing.
     // <signal.h> provided by C library.
     // <stdarg.h> provided by compiler.
-    module stdbool_h {
-      header "stdbool.h"
-      export *
-    }
+    // <stdbool.h> provided by compiler.
     module stddef_h {
       // <stddef.h>'s __need_* macros require textual inclusion.
       textual header "stddef.h"