Have Clang builders build in C++11 mode.

This ought to get us a little ahead on the transition.  Only minor fixes
are needed.  The one in MemoryBench is the most interesting: what used
to unambiguously be interpreted as concatenating two string literals is
now also ambiguously a user-defined literal; adding a space
disambiguates.

BUG=skia:
R=bungeman@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/361723002
diff --git a/bench/MemoryBench.cpp b/bench/MemoryBench.cpp
index 3fc46dc..f8af168 100644
--- a/bench/MemoryBench.cpp
+++ b/bench/MemoryBench.cpp
@@ -87,7 +87,7 @@
         } else if (write) {
             fName.appendf("_w");
         }
-        fName.appendf("_"SK_SIZE_T_SPECIFIER, num);
+        fName.appendf("_" SK_SIZE_T_SPECIFIER, num);
     }
 
     virtual bool isSuitableFor(Backend backend) SK_OVERRIDE {