Merge pull request #1154 from jnavarrom/issue#1074-build-for-iphoneos-arm64-with-crc

Enable crc instructions when building for arm64 cpu (iOS)

Author: weidai11

TestScripts/setenv-ios.sh

@@ -91,6 +91,7 @@ unset IOS_CFLAGS
 unset IOS_CXXFLAGS
 unset IOS_LDFLAGS
 unset IOS_SYSROOT
+unset CRC
 
 #########################################
 #####    Small Fixups, if needed    #####
@@ -133,6 +134,7 @@ fi
 
 if [[ "${IOS_CPU}" == "aarch64" || "${IOS_CPU}" == "arm64"* || "${IOS_CPU}" == "armv8"* ]] ; then
     IOS_CPU=arm64
+    CRC="-mcrc"
 fi
 
 echo "Configuring for ${IOS_SDK} (${IOS_CPU})"
@@ -282,7 +284,7 @@ if [ -z "${XCODE_SDK}" ]; then
 fi
 
 IOS_CFLAGS="-arch ${IOS_CPU} ${MIN_VER} -fno-common"
-IOS_CXXFLAGS="-arch ${IOS_CPU} ${MIN_VER} -stdlib=libc++ -fno-common"
+IOS_CXXFLAGS="-arch ${IOS_CPU} ${CRC} ${MIN_VER} -stdlib=libc++ -fno-common"
 IOS_SYSROOT="${XCODE_DEVELOPER_SDK}/${XCODE_SDK}"
 
 if [ ! -d "${IOS_SYSROOT}" ]; then