Use downloaded clang for building

clang.gypi

@@ -0,0 +1,49 @@
+{
+  'variables': {
+    # Clang stuff.
+    'make_clang_dir%': 'vendor/llvm-build/Release+Asserts',
+    # Set this to true when building with Clang.
+    'clang%': 1,
+    'conditions': [
+      ['OS=="win"', {
+        # Do not use Clang on Windows.
+        'clang%': 0,
+      }],
+    ],
+  },
+  'conditions': [
+    ['clang==1', {
+      'make_global_settings': [
+        ['CC', '<(make_clang_dir)/bin/clang'],
+        ['CXX', '<(make_clang_dir)/bin/clang++'],
+        ['CC.host', '$(CC)'],
+        ['CXX.host', '$(CXX)'],
+      ],
+      'target_defaults': {
+        'cflags_cc': [
+          '-std=c++11',
+        ],
+        'xcode_settings': {
+          'CC': '<(make_clang_dir)/bin/clang',
+          'LDPLUSPLUS': '<(make_clang_dir)/bin/clang++',
+          'OTHER_CFLAGS': [
+            '-fcolor-diagnostics',
+          ],
+
+          'GCC_C_LANGUAGE_STANDARD': 'c99',  # -std=c99
+          'CLANG_CXX_LIBRARY': 'libc++',  # -stdlib=libc++
+          'CLANG_CXX_LANGUAGE_STANDARD': 'c++11',  # -std=c++11
+        },
+        'target_conditions': [
+          ['_type in ["executable", "shared_library"]', {
+            'xcode_settings': {
+              # On some machines setting CLANG_CXX_LIBRARY doesn't work for
+              # linker.
+              'OTHER_LDFLAGS': [ '-stdlib=libc++' ],
+            },
+          }],
+        ],
+      },
+    }],  # clang==1
+  ],
+}

common.gypi

@@ -1,5 +1,6 @@
 {
   'includes': [
+    'clang.gypi',
     'vendor/brightray/brightray.gypi',
   ],
   'variables': {

vendor/brightray

@@ -1 +1 @@
-Subproject commit 89f8520322a1580657febac6529b2a2ead70f327
+Subproject commit 6de84e1d3a84555f6ca651ba1e75ecaf8582f95a