Fix single header build

build.bat

@@ -3,9 +3,10 @@ setlocal EnableDelayedExpansion
 
 set script_dir_backslash=%~dp0
 set script_dir=%script_dir_backslash:~0,-1%
+set build_dir=%script_dir%\Build
 
-if not exist Build mkdir Build
-pushd Build
+if not exist %build_dir% mkdir %build_dir%
+pushd %build_dir%
     REM Flags ======================================================================================
     REM MT   Static CRT
     REM EHa- Disable exception handling
@@ -14,7 +15,6 @@ pushd Build
     REM Oi   Use CPU Intrinsics
     REM Z7   Combine multi-debug files to one debug file
     set common_flags=-D DN_UNIT_TESTS_WITH_KECCAK %script_dir%\Source\Extra\dn_tests_main.cpp
-
     set msvc_driver_flags=%common_flags%        -MT -EHa -GR- -Od -Oi -Z7 -wd4201 -W4 -nologo
 
     REM Optionally pass `-analyze` to `msvc_compile_flags` for more checks, but,
@@ -33,9 +33,8 @@ pushd Build
         echo [BUILD] MSVC's cl detected, compiling ...
         set msvc_cmd=cl %msvc_compile_flags% %msvc_link_flags%
         powershell -Command "$time = Measure-Command { !msvc_cmd! | Out-Default }; Write-Host '[BUILD] msvc:'$time.TotalSeconds's'; exit $LASTEXITCODE" || exit /b 1
-
-        call cl %script_dir%\single_header_generator.cpp -nologo -link
-        call single_header_generator.exe %script_dir%\Source %script_dir%\Single_Header
+        call cl %script_dir%\single_header_generator.cpp -Z7 -nologo -link
+        call %build_dir%\single_header_generator.exe %script_dir%\Source %script_dir%\Single_Header
     )