Make ShBuiltInResources comparable with memcmp

Chromium builds a std::map with ShBuiltInResources as part of the key.
Comparator for == and < are needed for the map implementation.

Currently Chromium uses memcmp as the comparator. Padding
in ShBuiltInResources causes uninitialized reads.

Fix this by clearing the padding with memset during ShBuiltInResources
initialization.

Change-Id: I78aa3c59ce165503831aa2a67c96cf8af316c152
Reviewed-on: https://chromium-review.googlesource.com/223431
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>
Use windows_sdk_path for the 8.0 SDK path and windows_8_1_sdk_path for 8.1.

Change-Id: I0cb4262552852ccbc772ca828a0faa7d3e63784b
Reviewed-on: https://chromium-review.googlesource.com/224483
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
Always include precision in interm output if it's available

This helps with debugging precision propagation issues.

BUG=angle:787

Change-Id: Ia969481c8d933455cdafef4ae25c6ab3946bc1c2
Reviewed-on: https://chromium-review.googlesource.com/224281
Reviewed-by: Nicolas Capens <capn@chromium.org>
Reviewed-by: Shannon Woods <shannonwoods@chromium.org>
Tested-by: Shannon Woods <shannonwoods@chromium.org>