Externals: Update glslang to 16.0.0 and allow using system glslang

Externals/glslang/CMakeLists.txt

@@ -1,7 +1,6 @@
 set(ENABLE_PCH OFF)
 set(BUILD_EXTERNAL OFF)
 set(SKIP_GLSLANG_INSTALL ON)
-set(ENABLE_SPVREMAPPER OFF)
 set(ENABLE_GLSLANG_BINARIES OFF)
 set(ENABLE_HLSL OFF)
 set(ENABLE_OPT OFF)
@@ -10,5 +9,13 @@ set(ENABLE_EXCEPTIONS OFF)
 add_subdirectory(glslang)
 
 if (TARGET glslang)
+  target_include_directories(glslang
+  # Silence warnings on glslang by flagging it as a system include
+  SYSTEM PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/glslang>
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/glslang/Public>
+  PUBLIC
+    "${CMAKE_CURRENT_SOURCE_DIR}"
+  )
   dolphin_disable_warnings(glslang)
 endif()

Externals/glslang/exports.props

@@ -2,6 +2,7 @@
 <Project>
   <ItemDefinitionGroup>
     <ClCompile>
+      <AdditionalIncludeDirectories>$(ExternalsDir)glslang;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)glslang\glslang;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)glslang\glslang\glslang;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <AdditionalIncludeDirectories>$(ExternalsDir)glslang\glslang\glslang\Public;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>