restore spirv-sim substitution

Author: Keenuts

llvm/test/CodeGen/SPIRV/lit.local.cfg

@@ -1,7 +1,17 @@
 if not "SPIRV" in config.root.targets:
     config.unsupported = True
 
+spirv_sim_root = os.path.join(config.llvm_src_root, "utils", "spirv-sim")
+
 if config.spirv_tools_tests:
     config.available_features.add("spirv-tools")
     config.substitutions.append(("spirv-dis", os.path.join(config.llvm_tools_dir, "spirv-dis")))
     config.substitutions.append(("spirv-val", os.path.join(config.llvm_tools_dir, "spirv-val")))
+    config.substitutions.append(("spirv-as", os.path.join(config.llvm_tools_dir, "spirv-as")))
+    config.substitutions.append(
+      (
+        "spirv-sim",
+        "'%s' %s"
+        % (config.python_executable, os.path.join(spirv_sim_root, "spirv-sim.py")),
+      )
+    )