[Xcode] Disable a noisy warning.
diff --git a/llbuild.xcodeproj/project.pbxproj b/llbuild.xcodeproj/project.pbxproj
index f5da7aa..6655bed 100644
--- a/llbuild.xcodeproj/project.pbxproj
+++ b/llbuild.xcodeproj/project.pbxproj
@@ -2938,7 +2938,6 @@
 					"$(inherited)",
 					"\"BUILT_PRODUCTS_DIR=\\\"$(BUILT_PRODUCTS_DIR)\\\"\"",
 				);
-				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				INFOPLIST_FILE = utils/Xcode/LitXCTestAdaptor/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.apple.$(PRODUCT_NAME:rfc1034identifier)";
@@ -2958,7 +2957,6 @@
 					"$(inherited)",
 					"\"BUILT_PRODUCTS_DIR=\\\"$(BUILT_PRODUCTS_DIR)\\\"\"",
 				);
-				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				INFOPLIST_FILE = utils/Xcode/LitXCTestAdaptor/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.apple.$(PRODUCT_NAME:rfc1034identifier)";
@@ -3083,7 +3081,6 @@
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_SYMBOLS_PRIVATE_EXTERN = YES;
-				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
@@ -3138,7 +3135,6 @@
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREPROCESSOR_DEFINITIONS = NDEBUG;
 				GCC_SYMBOLS_PRIVATE_EXTERN = YES;
-				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 				GCC_WARN_UNDECLARED_SELECTOR = YES;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;