build: enable ClangCL compiler on Windows

Author: targos

common.gypi

@@ -155,6 +155,7 @@
             'ldflags': [ '-fPIC' ]
           }],
         ],
+        'msbuild_toolset': 'ClangCL',
         'msvs_settings': {
           'VCCLCompilerTool': {
             'BasicRuntimeChecks': 3,        # /RTC1
@@ -243,6 +244,7 @@
             'ldflags': [ '-fPIC' ]
           }],
         ],
+        'msbuild_toolset': 'ClangCL',
         'msvs_settings': {
           'VCCLCompilerTool': {
             'conditions': [