[Vulkan] Update glslang to 16.0.0 and introduce compat layer

src/xenia/gpu/premake5.lua

@@ -17,39 +17,44 @@ project("xenia-gpu")
   })
   includedirs({
     project_root.."/third_party/Vulkan-Headers/include",
+    project_root.."/third_party/glslang",  -- For glslang SPIRV headers
   })
   local_platform_files()
 
-group("src")
-project("xenia-gpu-shader-compiler")
-  uuid("ad76d3e4-4c62-439b-a0f6-f83fcf0e83c5")
-  kind("ConsoleApp")
-  language("C++")
-  links({
-    "dxbc",
-    "fmt",
-    "glslang-spirv",
-    "snappy",
-    "xenia-base",
-    "xenia-gpu",
-    "xenia-ui",
-    "xenia-ui-vulkan",
-  })
-  includedirs({
-    project_root.."/third_party/Vulkan-Headers/include",
-  })
-  files({
-    "shader_compiler_main.cc",
-    "../base/console_app_main_"..platform_suffix..".cc",
-  })
+if enableMiscSubprojects then
+  group("src")
+  project("xenia-gpu-shader-compiler")
+    uuid("ad76d3e4-4c62-439b-a0f6-f83fcf0e83c5")
+    kind("ConsoleApp")
+    language("C++")
+    links({
+      "dxbc",
+      "fmt",
+      "glslang-spirv",
+      "snappy",
+      "xenia-base",
+      "xenia-gpu",
+      "xenia-ui",
+      "xenia-ui-vulkan",
+    })
+    includedirs({
+      project_root.."/third_party/Vulkan-Headers/include",
+      project_root.."/third_party/glslang",  -- For glslang SPIRV headers
+    })
+    files({
+      "shader_compiler_main.cc",
+      "../base/console_app_main_"..platform_suffix..".cc",
+    })
 
-  filter("platforms:Windows")
-    -- Only create the .user file if it doesn't already exist.
-    local user_file = project_root.."/build/xenia-gpu-shader-compiler.vcxproj.user"
-    if not os.isfile(user_file) then
-      debugdir(project_root)
-      debugargs({
-        "2>&1",
-        "1>scratch/stdout-shader-compiler.txt",
-      })
-    end
+    filter("platforms:Windows")
+      -- Only create the .user file if it doesn't already exist.
+      local user_file = project_root.."/build/xenia-gpu-shader-compiler.vcxproj.user"
+      if not os.isfile(user_file) then
+        debugdir(project_root)
+        debugargs({
+          "2>&1",
+          "1>scratch/stdout-shader-compiler.txt",
+        })
+      end
+    filter({})
+end