eliminate python SyntaxWarnings from check-all output. #750

Job	Run time
abi-dump-setup	57s
Test llvm,clang,libclc / Lit Tests (ubuntu-latest)	52m 34s
Test llvm,clang,libclc / Lit Tests (windows-2019)	1h 8m 35s
Test llvm,clang,libclc / Lit Tests (macOS-11)	2h 48m 26s
Build lldb / Lit Tests (ubuntu-latest)	11m 59s
Build lldb / Lit Tests (windows-2019)	40m 23s
Test lld / Lit Tests (ubuntu-latest)	9m 16s
Build lldb / Lit Tests (macOS-11)	56m 16s
Test lld / Lit Tests (windows-2019)	19m 47s
Test lld / Lit Tests (macOS-11)	36m 58s
abi-dump (build-baseline)	31m 37s
abi-dump (build-latest)	30m 48s
abi-compare	30s
	8h 48m 6s

Provide feedback