[test] Rename all module.map files to module.modulemap

`module.map` as a module map name has been discouraged since 2014, and
Clang will soon warn on its usage. This patch renames all instances of
`module.map` in the Swift tests to `module.modulemap` in preparation
for this change to Clang.

rdar://106123303

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

@@ -0,0 +1,45 @@
+module ansible {
+  header "Ansible.h"
+  export *
+}
+module gizmo {
+  header "Gizmo.h"
+  export *
+}
+module ObjectiveC {
+  header "ObjectiveC.h"
+  export *
+}
+module Foundation {
+  header "BridgeTestFoundation.h"
+  export *
+}
+module CoreCooling {
+  header "CoreCooling.h"
+  export *
+}
+module UIKit {
+  header "UIKit.h"
+  export *
+}
+module AppKit {
+  header "AppKit.h"
+  export *
+}
+module CoreData {
+  header "CoreData.h"
+  export *
+}
+module Dispatch {
+  header "dispatch.h"
+  export *
+}
+
+module objc_extensions_helper {
+  header "objc_extensions_helper.h"
+}
+
+module NonNilTest {
+  header "NonNilTest.h"
+  export *
+}