When ANGLE_PROGRAM_BINARY_LOAD is enabled, Program::loadBinary
unconditionally returns angle::Result::Continue to the caller. The
caller, gl::Program::link, postpones the resolution of the link
until resolveLinkImpl.

Unfortunately, resolveLinkImpl is not able to tell whether the link
failed because the shader from the developer is bad or because the
loaded binary is not compatible with the backend. The former case
should fail link. In the latter case, we should fallback to linking
the program from the original shader sources. The loaded binary could
be read from the on-disk shader cache and be corrupted or serialized
with different revision and subsystem id than the currently loaded
ANGLE backend.

This fix adjusts Program::loadBinary and ProgramD3D::load so that
angle::Result::Incomplete is returned to gl::Program::link when the
binary is incompatible with the backend.  gl::Program:link falls back
to compilation from original shader sources.

Since no code checks the return value of SizedMRUCache::eraseByKey,
modified it to now return void.

Bug: chromium:1079497
Change-Id: Id5271d7badad8627563e87859d1c9fdb81de5785
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2197944Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Rafael Cintron <rafael.cintron@microsoft.com>