Reduce call to strlen when possible #4314

Job	Run time
Checks	5m 21s
ASAN_Tests_Debug	3m 33s
Clang_Unit_Build_Option_Tests	4m 20s
ASAN_Tests	3m 46s
Conformance_Tests_ESNext	2m 7s
Conformance_Tests_ESNext_Debug_A	2m 9s
Conformance_Tests_ESNext_Debug_B	1m 19s
ESP_IDF_Build_Test	3m 48s
ESP8266_RTOS_SDK_Build_Test	1m 27s
Linux_AArch64_Tests	4m 26s
Linux_AArch64_Tests_Debug	6m 29s
Linux_ARMv7l_Tests	4m 28s
Linux_ARMv7l_Tests_Debug	5m 57s
Linux_x86_cpointer-32bit_Build_Correctness_Tests	1m 49s
Linux_x86-64_Build_Correctness_Debugger_Tests	5m 0s
Linux_x86-64_Build_Option_Tests	4m 13s
MbedOS_K64F_Build_Test	1m 33s
Notification	0s
NuttX_STM32F4_Build_Test	2m 17s
OSX_x86-64_Build_Correctness_Unit_Tests	4m 34s
OSX_x86-64_Build_Correctness_Unit_Tests_Debug	3m 52s
RIOT_STM32F4_Build_Test	53s
UBSAN_Tests	2m 36s
Unit_Tests	1m 47s
Zephyr_STM32F4_Build_Test	4m 4s
	1h 21m 48s

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