Don't delete the module you're inspecting

Prior to this patch when you used `clang -module-file-info` clang would
delete the module on completion because the module was treated as an
output file.

This fixes the issue so you don't need to invoke cc1 directly to get
module file information.

Reviewed By: steven_wu, phosek

Differential Revision: https://reviews.llvm.org/D103547

clang/lib/Driver/Driver.cpp

@@ -4883,6 +4883,11 @@ const char *Driver::GetNamedOutputPath(Compilation &C, const JobAction &JA,
     return "-";
   }
 
+  if (JA.getType() == types::TY_ModuleFile &&
+      C.getArgs().getLastArg(options::OPT_module_file_info)) {
+    return "-";
+  }
+
   // Is this the assembly listing for /FA?
   if (JA.getType() == types::TY_PP_Asm &&
       (C.getArgs().hasArg(options::OPT__SLASH_FA) ||

clang/test/Modules/clang_module_file_info.m

@@ -0,0 +1,16 @@
+
+@import DependsOnModule;
+
+// RUN: rm -rf %t %t-obj
+// RUN: %clang_cc1 -w -Wunused -fmodules -fmodule-format=obj -fimplicit-module-maps -fdisable-module-hash -fmodules-cache-path=%t-obj -F %S/Inputs -DBLARG -DWIBBLE=WOBBLE -fmodule-feature myfeature %s
+// RUN: %clang -module-file-info %t-obj/DependsOnModule.pcm | FileCheck %s
+// RUN: %clang -module-file-info %t-obj/DependsOnModule.pcm | FileCheck %s
+
+// This test is just verifying that the clang driver doesn't delete the input
+// file when -module-file-info is passed. We verify this by dumping the module
+// twice subsequently. We have other tests to verify the contents of the module
+// and the tool output (see: module_file_info.m)
+
+// CHECK: Generated by this Clang:
+
+// CHECK: Module name: DependsOnModule