Make a module "use" also count as use of all its submodules

[klimek]

lg

[djasper]

Submitted as r232159.

lib/Lex/ModuleMap.cpp

do {
     Dir = SourceMgr.getFileManager().getDirectory(DirName);
   } while (Dir);
   return KnownHeader();
 }
 
 // Returns true if RequestingModule directly uses RequestedModule.
 static bool directlyUses(const Module *RequestingModule,
                          const Module *RequestedModule) {
-  return std::find(RequestingModule->DirectUses.begin(),
-                   RequestingModule->DirectUses.end(),
-                   RequestedModule) != RequestingModule->DirectUses.end();
+  for (const Module* DirectUse : RequestingModule->DirectUses) {
+    if (RequestedModule->isSubModuleOf(DirectUse))
+      return true;
+  }
+  return false;
 }
 
 static bool violatesPrivateInclude(Module *RequestingModule,
                                    const FileEntry *IncFileEnt,
                                    ModuleMap::ModuleHeaderRole Role,
                                    Module *RequestedModule) {
   bool IsPrivateRole = Role & ModuleMap::PrivateHeader;
 #ifndef NDEBUG

test/Modules/Inputs/declare-use/module.map

 
 module XG {
   header "g.h"
   header "g1.h"
   use XC
   use XE
   use XJ
   use XK
+  use XN
 }
 
 module XH {
   header "h.h"
   header "h1.h"
   header "s.h"
   use XC
   use XE
module XL {
   textual header "l.h"
 }
 
 module XM {
   private textual header "m.h"
   textual header "m2.h"
 }
 
+module XN {
+  module sub {
+    header "sub.h"
+  }
+}
+
 module XS {
 }

test/Modules/declare-use1.cpp

 // RUN: rm -rf %t
 // RUN: %clang_cc1 -fmodule-maps -fmodules-cache-path=%t -fmodules-decluse -fmodule-name=XG -I %S/Inputs/declare-use %s -verify
 
 #include "g.h"
 #include "e.h"
 #include "f.h" // expected-error {{module XG does not depend on a module exporting 'f.h'}}
 #include "i.h"
-const int g2 = g1 + e + f + aux_i;
+#include "sub.h"
+const int g2 = g1 + e + f + aux_i + sub;