Add -fms-compatibility-version=19 to the clang-cl self-host
Add -fms-compatibility-version=19 to the clang-cl self-host

Otherwise, we get errors about char16_t and char32_t during the stage 2
build.

Also, fix a bug where cflags, cxxflags, and ldflags all pointed to the
same list.
R=hans@chromium.org
BUG=597854

Review URL: https://codereview.chromium.org/1832093002 .

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#383288}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk