SPV: Implement new extensions GL_KHX_device_group and GL_KHX_multiview.

These correspond to SPV_KHR_device_group and SPV_KHR_multiview.
Also, bring tests up to date with Khronos internals, and some misc. related changes.

gtests/Spv.FromFile.cpp

@@ -225,7 +225,9 @@ INSTANTIATE_TEST_CASE_P(
         "spv.dataOutIndirect.vert",
         "spv.deepRvalue.frag",
         "spv.depthOut.frag",
+        "spv.deviceGroup.frag",
         "spv.discard-dce.frag",
+        "spv.drawParams.vert",
         "spv.doWhileLoop.frag",
         "spv.earlyReturnDiscard.frag",
         "spv.flowControl.frag",
@@ -234,8 +236,10 @@ INSTANTIATE_TEST_CASE_P(
         "spv.functionCall.frag",
         "spv.functionNestedOpaque.vert",
         "spv.functionSemantics.frag",
+        "spv.GeometryShaderPassthrough.geom",
         "spv.interpOps.frag",
         "spv.int64.frag",
+        "spv.intOps.vert",
         "spv.layoutNested.vert",
         "spv.length.frag",
         "spv.localAggregates.frag",
@@ -248,16 +252,17 @@ INSTANTIATE_TEST_CASE_P(
         "spv.merge-unreachable.frag",
         "spv.multiStruct.comp",
         "spv.multiStructFuncall.frag",
+        "spv.multiView.frag",
         "spv.newTexture.frag",
         "spv.noDeadDecorations.vert",
         "spv.nonSquare.vert",
+        "spv.noWorkgroup.comp",
         "spv.offsets.frag",
         "spv.Operations.frag",
-        "spv.intOps.vert",
-        "spv.noWorkgroup.comp",
         "spv.precision.frag",
         "spv.prepost.frag",
         "spv.qualifiers.vert",
+        "spv.sampleMaskOverrideCoverage.frag",
         "spv.shaderBallot.comp",
         "spv.shaderDrawParams.vert",
         "spv.shaderGroupVote.comp",