fix: append instead of rewrite

Makefile

@@ -40,44 +40,44 @@ BUILD_TARGET_FLAGS = -S cmake
 # flags for xcode 15.4
 ifeq ($(IREE_BUILD_TARGET), host)
 else ifeq ($(IREE_BUILD_TARGET), ios)
-	BUILD_TARGET_FLAGS = \
+	BUILD_TARGET_FLAGS += \
 		-DCMAKE_SYSTEM_NAME=iOS\
 		-DCMAKE_OSX_DEPLOYMENT_TARGET=17.5\
 		-DCMAKE_OSX_ARCHITECTURES=arm64\
 		-DCMAKE_SYSTEM_PROCESSOR=arm64\
 		-DCMAKE_IOS_INSTALL_COMBINED=YES\
 		-DCMAKE_OSX_SYSROOT=$(shell xcodebuild -version -sdk iphoneos Path)
 else ifeq ($(IREE_BUILD_TARGET), ios_simulator)
-	BUILD_TARGET_FLAGS = \
+	BUILD_TARGET_FLAGS += \
 		-DCMAKE_SYSTEM_NAME=iOS\
 		-DCMAKE_OSX_DEPLOYMENT_TARGET=17.5\
 		-DCMAKE_OSX_ARCHITECTURES=arm64\
 		-DCMAKE_SYSTEM_PROCESSOR=arm64\
 		-DCMAKE_IOS_INSTALL_COMBINED=YES\
 		-DCMAKE_OSX_SYSROOT=$(shell xcodebuild -version -sdk iphonesimulator Path)
 else ifeq ($(IREE_BUILD_TARGET), visionos)
-	BUILD_TARGET_FLAGS = \
+	BUILD_TARGET_FLAGS += \
 		-DCMAKE_SYSTEM_NAME=visionOS\
 		-DCMAKE_OSX_DEPLOYMENT_TARGET=1.2\
 		-DCMAKE_OSX_ARCHITECTURES=arm64\
 		-DCMAKE_SYSTEM_PROCESSOR=arm64\
 		-DCMAKE_OSX_SYSROOT=$(shell xcodebuild -version -sdk xros Path)
 else ifeq ($(IREE_BUILD_TARGET), visionos_simulator)
-	BUILD_TARGET_FLAGS = \
+	BUILD_TARGET_FLAGS += \
 		-DCMAKE_SYSTEM_NAME=visionOS\
 		-DCMAKE_OSX_DEPLOYMENT_TARGET=1.2\
 		-DCMAKE_OSX_ARCHITECTURES=arm64\
 		-DCMAKE_SYSTEM_PROCESSOR=arm64\
 		-DCMAKE_OSX_SYSROOT=$(shell xcodebuild -version -sdk xrsimulator Path)
 else ifeq ($(IREE_BUILD_TARGET), tvos)
-	BUILD_TARGET_FLAGS = \
+	BUILD_TARGET_FLAGS += \
 		-DCMAKE_SYSTEM_NAME=tvOS\
 		-DCMAKE_OSX_DEPLOYMENT_TARGET=17.5\
 		-DCMAKE_OSX_ARCHITECTURES=arm64\
 		-DCMAKE_SYSTEM_PROCESSOR=arm64\
 		-DCMAKE_OSX_SYSROOT=$(shell xcodebuild -version -sdk appletvos Path)
 else ifeq ($(IREE_BUILD_TARGET), tvos_simulator)
-	BUILD_TARGET_FLAGS = \
+	BUILD_TARGET_FLAGS += \
 		-DCMAKE_SYSTEM_NAME=tvOS\
 		-DCMAKE_OSX_DEPLOYMENT_TARGET=17.5\
 		-DCMAKE_OSX_ARCHITECTURES=arm64\