Fix arrow function parsing #4116

Job	Run time
Linux_x86-64_Build_Correctness_Debugger_Tests	5m 6s
Checks	5m 13s
Linux_x86_cpointer-32bit_Build_Correctness_Tests	1m 36s
ASAN_Tests_Debug	3m 26s
ASAN_Tests	3m 22s
Clang_Unit_Build_Option_Tests	4m 19s
Conformance_Tests_ESNext	2m 17s
Conformance_Tests_ESNext_Debug_A	2m 8s
Conformance_Tests_ESNext_Debug_B	1m 19s
ESP_IDF_Build_Test	4m 24s
ESP8266_RTOS_SDK_Build_Test	1m 37s
Linux_AArch64_Tests	4m 16s
Linux_AArch64_Tests_Debug	6m 14s
Linux_ARMv7l_Tests	3m 57s
Linux_x86-64_Build_Option_Tests	4m 22s
Linux_ARMv7l_Tests_Debug	5m 52s
MbedOS_K64F_Build_Test	1m 31s
Notification	0s
NuttX_STM32F4_Build_Test	2m 3s
OSX_x86-64_Build_Correctness_Unit_Tests	3m 14s
OSX_x86-64_Build_Correctness_Unit_Tests_Debug	6h 0m 18s
RIOT_STM32F4_Build_Test	1m 2s
UBSAN_Tests	2m 12s
Unit_Tests	1m 51s
Zephyr_STM32F4_Build_Test	3m 4s
	7h 14m 43s

Provide feedback