Merge commit 'e157435c1e77' into update-shaderc

This brings in SDK-candidate-2 for the Vulkan SDK release incorporating
support for provisional raytracing features.

e157435c Bump revision.
e7c94f49 Merge pull request #2166 from alelenv/rq_lvalue_fix
f986436a Error assigns to objects of rayQueryEXT type.
08c02ced Merge pull request #2164 from dj2/unused
d50acf97 Remove unused variables.
344bd088 Merge pull request #2162 from ntfshard/small_fix
83855b97 Fix #2163: improve comments for addProcess() and the preamble.
1dad9200 printf format
988cd676 unused var
7fc409ee bitwise on boolean
f6802454 opposite inner condition
bfe4c595 Merge pull request #2160 from greg-lunarg/kg110
386f18cc Update spirv-tools known_good to latest stable
4d7c749b Merge pull request #2159 from neslimsah/master
99508c1c Merge pull request #2157 from neslimsah/master
2b4d345d accelerationStructureEXT - issue #2152
915f1191 accelerationStructureEXT - issue #2152
054b5e35 pass by reference updates
b366a703 Merge branch 'master' of
7d37a68a pass-by-reference updates
575f9df9 Merge pull request #1 from KhronosGroup/master

Testing: on Linux; unit tests on Windows
Change-Id: I9065ca3f579c975ba5fa7d2859a22201eade4e27