Merge pull request KhronosGroup#315 from bashbaug/fix-SPV_KHR_shader_clock

decouple SPV_KHR_shader_clock from the Shader capability

Author: johnkslang

include/spirv/unified1/spirv.core.grammar.json

@@ -4751,7 +4751,6 @@
         { "kind" : "IdScope", "name" : "'Scope'" }
       ],
       "capabilities" : [ "ShaderClockKHR" ],
-      "extensions" : [ "SPV_KHR_shader_clock" ],
       "version" : "None"
     },
     {
@@ -14128,7 +14127,6 @@
         {
           "enumerant" : "ShaderClockKHR",
           "value" : 5055,
-          "capabilities" : [ "Shader" ],
           "extensions" : [ "SPV_KHR_shader_clock" ],
           "version" : "None"
         },