SILGen: remove duplicated module declaration

This module was specified in the IDE and SILGen testing module maps,
which causes a failure.  Remove the duplicated declaration in the
SILGen inputs and use IDE's definition.

Author: compnerd

test/IDE/Inputs/custom-modules/Newtype.h

@@ -128,3 +128,6 @@ extern void mutate_TRefRef(_Null_unspecified TRefRef* _Null_unspecified)
     __attribute((swift_name("TRefRef.mutate(self:)")));
 extern void use_ConstTRef(_Null_unspecified ConstTRefRef)
     __attribute((swift_name("ConstTRefRef.use(self:)")));
+
+typedef NSString *MyString __attribute__((__swift_newtype__(struct)));
+

test/SILGen/Inputs/usr/include/module.map

@@ -35,11 +35,6 @@ module objc_extensions_helper {
   header "objc_extensions_helper.h"
 }
 
-module Newtype {
-  header "newtype.h"
-  export *
-}
-
 module NonNilTest {
   header "NonNilTest.h"
   export *

test/SILGen/newtype.swift

@@ -1,7 +1,7 @@
-
-// RUN: %target-swift-emit-silgen -module-name newtype -sdk %S/Inputs -I %S/Inputs -enable-source-import  %s | %FileCheck %s -check-prefix=CHECK-RAW
-
-// RUN: %target-swift-emit-sil -module-name newtype -sdk %S/Inputs -I %S/Inputs -enable-source-import  %s | %FileCheck %s -check-prefix=CHECK-CANONICAL
+// RUN: %empty-directory(%t)
+// RUN: %build-silgen-test-overlays
+// RUN: %target-swift-emit-silgen(mock-sdk: %clang-importer-sdk -I %t) -module-name newtype -I %S/Inputs -I %S/Inputs -I %S/../IDE/Inputs/custom-modules -enable-objc-interop -enable-source-import %s | %FileCheck %s -check-prefix=CHECK-RAW
+// RUN: %target-swift-emit-sil(mock-sdk: %clang-importer-sdk -I %t) -module-name newtype -I %S/Inputs -I %S/Inputs -I %S/../IDE/Inputs/custom-modules -enable-objc-interop -enable-source-import %s | %FileCheck %s -check-prefix=CHECK-CANONICAL
 
 // REQUIRES: objc_interop