Add Python\pyarena.c to the VC project file.
Fix the definition of BUILD in the VC project settings.
diff --git a/PCbuild/pythoncore.vcproj b/PCbuild/pythoncore.vcproj
index 48d1489..d220d35 100644
--- a/PCbuild/pythoncore.vcproj
+++ b/PCbuild/pythoncore.vcproj
@@ -1428,7 +1428,7 @@
 					Name="VCCLCompilerTool"
 					Optimization="2"
 					AdditionalIncludeDirectories=""
-					PreprocessorDefinitions="BUILD=60"/>
+					PreprocessorDefinitions="BUILD=\"60\""/>
 			</FileConfiguration>
 			<FileConfiguration
 				Name="Debug|Win32">
@@ -1436,7 +1436,7 @@
 					Name="VCCLCompilerTool"
 					Optimization="0"
 					AdditionalIncludeDirectories=""
-					PreprocessorDefinitions="BUILD=60"/>
+					PreprocessorDefinitions="BUILD=\&quot;60\&quot;"/>
 			</FileConfiguration>
 			<FileConfiguration
 				Name="ReleaseItanium|Win32">
@@ -1444,7 +1444,7 @@
 					Name="VCCLCompilerTool"
 					Optimization="2"
 					AdditionalIncludeDirectories=""
-					PreprocessorDefinitions="BUILD=60"/>
+					PreprocessorDefinitions="BUILD=\&quot;60\&quot;"/>
 			</FileConfiguration>
 		</File>
 		<File
@@ -2516,6 +2516,9 @@
 			</FileConfiguration>
 		</File>
 		<File
+			RelativePath="..\Python\pyarena.c">
+		</File>
+		<File
 			RelativePath="..\Python\pyfpe.c">
 			<FileConfiguration
 				Name="Release|Win32">