Merge remote-tracking branch 'aosp/upstream-master' into update-shaderc

Includes the following:
427daa5 Update tests for more strict glslang
2df47b5 Add -flimit to glslc to support shader resource limits.
9d52054 Indicate Shaderc's level of stability.
1ef0a89 Support resource limits in C, C++ API
89eefb9 Add -fentry-point to glslc
725a8fd Update READMEs.
4b8ad0e Add source/parsed_operand.cpp to SPIRV-Tools
38bd2b0 Some source files are renamed in SPIRV-Tools.
fc71c2f Added SPIRV-Tools source file validate_datarules.cpp
f036381 C, C++ APIs are sensitive to entry_point_name
aaa8b0c Removed SPIRV-Tools source/instruction.cpp
525a48c Add glslang source file hlsl/hlslAttributes.cpp
cdefe18 glslc: expose HLSL compilation support from Glslang
fa93320 Add API support for compiling HLSL
e6b4795 Rename GlslInitialzer -> GlslangInitializer
a39e3cf Ignore .DS_Store files

Test: checkbuild.py on Linux x86; unit tests on Windows
Change-Id: Ia3c8c4ef67bac740818b1a0ef0089159a4a40535