Add --strip-reflect pass

Strips reflection info. This is limited to decorations and
decoration instructions related to the SPV_GOOGLE_hlsl_functionality1
extension.
It will remove the OpExtension for SPV_GOOGLE_hlsl_functionality1.
It will also remove the OpExtension for SPV_GOOGLE_decorate_string
if there are no further remaining uses of OpDecorateStringGOOGLE.

Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/1398
diff --git a/include/spirv-tools/optimizer.hpp b/include/spirv-tools/optimizer.hpp
index bedf436..03eb1c2 100644
--- a/include/spirv-tools/optimizer.hpp
+++ b/include/spirv-tools/optimizer.hpp
@@ -133,6 +133,13 @@
 // Section 3.32.2 of the SPIR-V spec) of the SPIR-V module to be optimized.
 Optimizer::PassToken CreateStripDebugInfoPass();
 
+// Creates a strip-reflect-info pass.
+// A strip-reflect-info pass removes all reflections instructions.
+// For now, this is limited to removing decorations defined in
+// SPV_GOOGLE_hlsl_functionality1.  The coverage may expand in
+// the future.
+Optimizer::PassToken CreateStripReflectInfoPass();
+
 // Creates an eliminate-dead-functions pass.
 // An eliminate-dead-functions pass will remove all functions that are not in
 // the call trees rooted at entry points and exported functions.  These