Use whole program optimization

CMakeLists.txt

@@ -65,6 +65,9 @@ if (${VCPKG_TARGET_TRIPLET} MATCHES ".*-static")
   foreach(CompilerFlag ${CompilerFlags})
     string(REPLACE "/MD" "/MT" ${CompilerFlag} "${${CompilerFlag}}")
   endforeach()
+  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /GL")
+  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} /GL")
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /LTCG")
   # Need explicit dependencies on wx's dependencies
   find_package(png REQUIRED)
   find_package(tiff REQUIRED)

CMakeSettings.json

@@ -51,7 +51,7 @@
     {
       "name": "x86-Release-static",
       "generator": "Ninja",
-      "configurationType": "RelWithDebInfo",
+      "configurationType": "Release",
       "buildRoot": "${projectDir}\\out\\build\\${name}",
       "installRoot": "${projectDir}\\out\\install\\${name}",
       "cmakeCommandArgs": "-DVCPKG_TARGET_TRIPLET=x86-windows-static",