Merge 53501 and 53502 from 25 branch:
Add /GS- for AMD64 and Itanium builds where missing.
diff --git a/PCbuild/pythonw.vcproj b/PCbuild/pythonw.vcproj
index 2cc7d61..d00142f 100644
--- a/PCbuild/pythonw.vcproj
+++ b/PCbuild/pythonw.vcproj
@@ -130,7 +130,7 @@
 			ATLMinimizesCRunTimeLibraryUsage="FALSE">
 			<Tool
 				Name="VCCLCompilerTool"
-				AdditionalOptions=" /USECL:MS_ITANIUM"
+				AdditionalOptions=" /USECL:MS_ITANIUM /GS-"
 				Optimization="2"
 				InlineFunctionExpansion="1"
 				AdditionalIncludeDirectories="..\Include,..\PC"