[mlir][spirv] Support SPIR-V 1.6 in deserializer (#151958)

After skimming through the changes in the spec, there does not seem to
be anything that will cause issues. A new roundtrip test has been added
and validate with `spirv-val` just in case.

Author: IgWod-IMG

mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp

@@ -138,6 +138,7 @@ LogicalResult spirv::Deserializer::processHeader() {
       MIN_VERSION_CASE(3);
       MIN_VERSION_CASE(4);
       MIN_VERSION_CASE(5);
+      MIN_VERSION_CASE(6);
 #undef MIN_VERSION_CASE
     default:
       return emitError(unknownLoc, "unsupported SPIR-V minor version: ")

mlir/test/Target/SPIRV/module.mlir

@@ -20,6 +20,12 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.5, [Shader], []> {
 
 // -----
 
+// CHECK: v1.6
+spirv.module Logical GLSL450 requires #spirv.vce<v1.6, [Shader, Linkage], []> {
+}
+
+// -----
+
 // CHECK: [Shader, Float16]
 spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader, Float16], []> {
 }