The old ShCompile will be removed and replaced with sh::Compile in
ANGLE to avoid conflicting with glslang's identically named methods.

BUG=angleproject:1319
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2610603002
Cr-Commit-Position: refs/heads/master@{#441166}