CMake: make SWIFTSHADER_DCHECK_ALWAYS_ON work on Windows

Bug: b/145758253
Change-Id: Ie444337ea0efe91820d64400a857136f800cd3d6
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/42788
Presubmit-Ready: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Antonio Maiorano <amaiorano@google.com>

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 783d14a..7177635 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -505,10 +505,6 @@
         set_cpp_flag("-s" RELEASE)
     endif()
 
-    if(SWIFTSHADER_DCHECK_ALWAYS_ON)
-        list(APPEND SWIFTSHADER_COMPILE_OPTIONS "-DDCHECK_ALWAYS_ON")
-    endif()
-
     # For distribution it is more important to be slim than super optimized
     set_cpp_flag("-Os" RELEASE)
     set_cpp_flag("-Os" RELWITHDEBINFO)
@@ -539,6 +535,10 @@
     endif()
 endif()
 
+if(SWIFTSHADER_DCHECK_ALWAYS_ON)
+    list(APPEND SWIFTSHADER_COMPILE_OPTIONS "-DDCHECK_ALWAYS_ON")
+endif()
+
 if(SWIFTSHADER_WARNINGS_AS_ERRORS)
     if(MSVC)
         set(WARNINGS_AS_ERRORS "/WX")  # Treat all warnings as errors