AArch64 objc_msgSend: Fix argument corruption due to invalid stack pointer offset (#266)

* Fix argument corruption due to invalid sp offset

* Bump runtime version

Test/CMakeLists.txt

@@ -134,9 +134,9 @@ function(addtest_flags TEST_NAME FLAGS TEST_SOURCE)
 endfunction(addtest_flags)
 
 function(addtest_variants TEST TEST_SOURCE LEGACY)
-	addtest_flags(${TEST} "-O0 -fobjc-runtime=gnustep-2.0 -UNDEBUG -DGS_RUNTIME_V2" "${TEST_SOURCE}")
+	addtest_flags(${TEST} "-O0 -fobjc-runtime=gnustep-2.2 -UNDEBUG -DGS_RUNTIME_V2" "${TEST_SOURCE}")
 	target_sources(${TEST} PRIVATE $<TARGET_OBJECTS:test_runtime>)
-	addtest_flags("${TEST}_optimised" "-O3 -fobjc-runtime=gnustep-2.0 -UNDEBUG -DGS_RUNTIME_V2" "${TEST_SOURCE}")
+	addtest_flags("${TEST}_optimised" "-O3 -fobjc-runtime=gnustep-2.2 -UNDEBUG -DGS_RUNTIME_V2" "${TEST_SOURCE}")
 	target_sources("${TEST}_optimised" PRIVATE $<TARGET_OBJECTS:test_runtime>)
 
 	# -fobjc-arc is not supported on platforms using the legacy runtime

objc_msgSend.aarch64.S

@@ -169,7 +169,7 @@ CDECL(objc_msgSend_stret):
 	EH_NOP
 	ldp    x2, x3, [sp, #32]
 	EH_NOP
-	ldp    x4, x5, [sp, #64]
+	ldp    x4, x5, [sp, #48]
 	EH_NOP
 	ldp    x6, x7, [sp, #64]
 	EH_NOP