Bug 1160897 - Fixing .ycm_extra_conf for Fennec. r=ehsan

Looks like ycmd fails to parse the file if the -march=arm* option is given
Removing it doesn't solve all YCM problems for Fennec, but it allows us
to use JumpToDefinition, GetType and semantic auto-completion.

.ycm_extra_conf.py

@@ -21,7 +21,14 @@ def FlagsForFile(filename):
     out.encoding = None
     mach.run(['compileflags', filename], stdout=out, stderr=out)
 
+    flag_list = shlex.split(out.getvalue())
+
+    # This flag is added by Fennec for android build and causes ycmd to fail to parse the file.
+    # Removing this flag is a workaround until ycmd starts to handle this flag properly.
+    # https://github.com/Valloric/YouCompleteMe/issues/1490
+    final_flags = [x for x in flag_list if not x.startswith('-march=armv')]
+
     return {
-        'flags': shlex.split(out.getvalue()),
+        'flags': final_flags,
         'do_cache': True
     }