The //build/config/gcc:symbol_visibility_hidden config was removed in an
attempt to improve stack traces on Linux. However, this resulted in the
in-class-inline-functions in glslang to be weak symbols.  The KHR dEQP
tests link against glslang as well as libGLESv2.so, resulting in
angle_deqp_khr_gles*_tests to link those weak symbols.  Due to glslang's
usage of a global variable in InitializeDll.cpp, a bug is created where
ANGLE sometimes calls into its own copy of glslang and sometimes the KHR
dEQP's version, with the two copies of the global variable being
inconsistent.

Bug: angleproject:4123
Change-Id: I0cfe3236117b1219db4fea4495e1583334c04fbe
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1926887Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>