[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/IRGen/Inputs/usr/include/module.modulemap

@@ -0,0 +1,40 @@
+
+module gizmo {
+  header "Gizmo.h"
+  export *
+}
+
+module SRoA {
+  header "SRoA.h"
+  export *
+}
+
+module ObjectiveC {
+  header "BridgeTestObjectiveC.h"
+  export *
+}
+
+module CoreCooling {
+  header "CoreCooling.h"
+  export *
+}
+
+module Foundation {
+  header "BridgeTestFoundation.h"
+  export *
+}
+
+module CoreFoundation {
+  header "BridgeTestCoreFoundation.h"
+  export *
+}
+
+module ObjCInterop {
+  header "ObjCInterop.h"
+  export *
+}
+
+module error_domains {
+  header "error_domains.h"
+  export *
+}