[modules] Add module maps for LLVM. These are not quite ready for prime-time

yet, but only a few more Clang patches need to land. (I have 'ninja check'
passing locally.)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209269 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bitcode/module.modulemap

@@ -0,0 +1 @@
+module Bitcode { requires cplusplus umbrella "." module * { export * } }