Fix module map to create a module for the configured header Config/abi-breaking.h

A client of a header that relies on ABI breaking should get the macro
exported there.
Before this, the unittest for Support/Error including Support/Error.h
didn't get the macro exported by the Support module, because the
latter only re-export its submodules and included module, not
textual headers.

Hopefully, it'll also fix the build with local submodule visibility,
since the LLVM_Utils contains two submodules: ADT and Support. They
both include abi-breaking.h that defines a symbol. The textual
inclusion lead to a double definition of the symbol which broke
the parent module.

Differential Revision: https://reviews.llvm.org/D27273

llvm-svn: 288400

include/llvm/module.modulemap.build

@@ -3,3 +3,7 @@ module LLVM_Support_DataTypes {
   header "Support/DataTypes.h"
   export *
 }
+module LLVM_Config_ABI_Breaking {
+  header "Config/abi-breaking.h"
+  export *
+}