-gmodules: Emit debug info for implicit module imports via #include.

When a type is only used as a template parameter and that type is the
only type imported from another #include'd module, no skeleton CU for
that module is generated, so a consumer doesn't know where to find the
type definition. By emitting an import declaration, we can force a
skeleton CU to be generated for each imported module.

rdar://problem/36266156

llvm-svn: 321754
diff --git a/clang/test/Modules/ExtDebugInfo.cpp b/clang/test/Modules/ExtDebugInfo.cpp
index 97386bc..c57f1f0 100644
--- a/clang/test/Modules/ExtDebugInfo.cpp
+++ b/clang/test/Modules/ExtDebugInfo.cpp
@@ -187,7 +187,7 @@
 
 // CHECK: !DIGlobalVariable(name: "anon_enum", {{.*}}, type: ![[ANON_ENUM:[0-9]+]]
 // CHECK: !DICompositeType(tag: DW_TAG_enumeration_type, scope: ![[NS]],
-// CHECK-SAME:             line: 16
+// CHECK-SAME:             line: 19
 
 // CHECK: !DIGlobalVariable(name: "GlobalUnion",
 // CHECK-SAME:              type: ![[GLOBAL_UNION:[0-9]+]]