ES6 template literals should not use legacy octal strings

Correctly handle SyntaxErrors in escape sequences.

BUG=v8:3736
LOG=Y
R=dslomov@chromium.org, caitpotter88@gmail.com

Review URL: https://codereview.chromium.org/811113002

Cr-Commit-Position: refs/heads/master@{#25891}
Ship ES6 template literals

BUG=v8:3230
LOG=Y
R=dslomov@chromium.org, caitpotter88@gmail.com

Review URL: https://codereview.chromium.org/808413004

Cr-Commit-Position: refs/heads/master@{#25892}
Define SDKROOT for Mac

otherwise, the clang we ship doesn't work

BUG=none
R=adamk@chromium.org,thakis@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/792783006

Cr-Commit-Position: refs/heads/master@{#25893}