Use 'rc' resource compiler with clang-cl toolchain

The LLVM toolchain doesn't come with a Windows resource compiler at
the moment. Use 'rc' from the Windows SDK.

mesonbuild/modules/windows.py

@@ -60,7 +60,7 @@ class WindowsModule(ExtensionModule):
 
         if not rescomp or not rescomp.found():
             comp = self.detect_compiler(state.compilers)
-            if comp.id == 'msvc':
+            if comp.id == 'msvc' or comp.id == 'clang-cl':
                 rescomp = ExternalProgram('rc', silent=True)
             else:
                 rescomp = ExternalProgram('windres', silent=True)

run_unittests.py

@@ -3070,7 +3070,7 @@ class WindowsTests(BasePlatformTests):
 
         # resource compiler depfile generation is not yet implemented for msvc
         env = get_fake_env(testdir, self.builddir, self.prefix)
-        depfile_works = env.detect_c_compiler(False).get_id() != 'msvc'
+        depfile_works = env.detect_c_compiler(False).get_id() not in ['msvc', 'clang-cl']
 
         self.init(testdir)
         self.build()