gh-108374: Add --disable-gil option to PCbuild/build.bat (#108729)

This adds a `--disable-gil` option to PCbuild/build.bat. For now, all
this does is define the Py_NOGIL macro.

Author: colesbury

PCbuild/build.bat

@@ -33,6 +33,7 @@ echo.  -k  Attempt to kill any running Pythons before building (usually done
 echo.      automatically by the pythoncore project)
 echo.  --pgo          Build with Profile-Guided Optimization.  This flag
 echo.                 overrides -c and -d
+echo.  --disable-gil  Enable experimental support for running without the GIL.
 echo.  --test-marker  Enable the test marker within the build.
 echo.  --regen        Regenerate all opcodes, grammar and tokens.
 echo.
@@ -80,6 +81,7 @@ if "%~1"=="-q" (set verbose=/v:q /nologo /clp:summary) & shift & goto CheckOpts
 if "%~1"=="-k" (set kill=true) & shift & goto CheckOpts
 if "%~1"=="--pgo" (set do_pgo=true) & shift & goto CheckOpts
 if "%~1"=="--pgo-job" (set do_pgo=true) & (set pgo_job=%~2) & shift & shift & goto CheckOpts
+if "%~1"=="--disable-gil" (set UseDisableGil=true) & shift & goto CheckOpts
 if "%~1"=="--test-marker" (set UseTestMarker=true) & shift & goto CheckOpts
 if "%~1"=="-V" shift & goto Version
 if "%~1"=="--regen" (set Regen=true) & shift & goto CheckOpts
@@ -172,6 +174,7 @@ echo on
  /p:IncludeExternals=%IncludeExternals%^
  /p:IncludeCTypes=%IncludeCTypes%^
  /p:IncludeSSL=%IncludeSSL% /p:IncludeTkinter=%IncludeTkinter%^
+ /p:DisableGil=%UseDisableGil%^
  /p:UseTestMarker=%UseTestMarker% %GITProperty%^
  %1 %2 %3 %4 %5 %6 %7 %8 %9
 

PCbuild/pyproject.props

@@ -40,6 +40,7 @@
     <ClCompile>
       <AdditionalIncludeDirectories>$(PySourcePath)Include;$(PySourcePath)Include\internal;$(PySourcePath)PC;$(IntDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>WIN32;$(_Py3NamePreprocessorDefinition);$(_PlatformPreprocessorDefinition)$(_DebugPreprocessorDefinition)$(_PydPreprocessorDefinition)%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions Condition="'$(DisableGil)' == 'true'">Py_NOGIL=1;%(PreprocessorDefinitions)</PreprocessorDefinitions>
 
       <Optimization>MaxSpeed</Optimization>
       <IntrinsicFunctions>true</IntrinsicFunctions>