Reland Make clang the default on linux.

build/standalone.gypi

Index: build/standalone.gypi
diff --git a/build/standalone.gypi b/build/standalone.gypi
index c0979a8f6e46a6823110e14e3ae2d3b85f5f8781..f99e670a8fddf446eafb1b2258592aff3c65abd3 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -120,7 +120,13 @@
       }, {
         'v8_enable_gdbjit%': 0,
       }],
-      ['OS=="mac"', {
+      ['OS=="linux" and \
+        (v8_target_arch!="arm" or target_arch!="arm") and \

[jochen (gone - plz use gerrit), 2015/01/21 15:26:08]

target_arch should be enough. If you cross compile and use the simulator, using
clang is ok.

+        (v8_target_arch!="arm64" or target_arch!="arm64") and \
+        (v8_target_arch!="mips" or target_arch!="mips") and \
+        (v8_target_arch!="mipsel" or target_arch!="mipsel") and \
+        (v8_target_arch!="mips64el" or target_arch!="mips64el") or \
+        OS=="mac"', {
         'clang%': 1,
       }, {
         'clang%': 0,