Add CHARS_ALPHA and _StripEscapeSequences #5477

Job	Run time
Cross compiler for s390x	5m 45s
Test in OpenBSD	5m 6s
testinstall - - ubuntu-latest	5m 0s
teststandard - - ubuntu-latest	6m 7s
testmanuals - - ubuntu-latest	5m 54s
testexpect testmockpkg testspecial test-compile testlibgap testkernel testworkspace - - ubuntu-latest	4m 5s
testpackages testinstall-loadall - - ubuntu-latest	6m 5s
makemanuals testmakeinstall - CONFIGFLAGS="--prefix=/tmp/gapprefix" NO_COVERAGE=1 - ubuntu-latest	5m 12s
teststandard - ABI=32 CONFIGFLAGS="" - ubuntu-20.04	5m 59s
testinstall - HPCGAP=yes ABI=64 - ubuntu-latest	5m 52s
testmockpkg testinstall - BOOTSTRAP_MINIMAL=yes - macos-latest	5m 53s
testbugfix - CONFIGFLAGS="--enable-memory-checking" - ubuntu-latest	5m 56s
testbuildsys testmockpkg testinstall - NO_COVERAGE=1 ABI=64 BUILDDIR=out-of-tree CONFIGFLAGS="--enable-valgrind" - ubuntu-latest	4m 14s
testbuildsys testmockpkg testinstall - NO_COVERAGE=1 ABI=32 BUILDDIR=out-of-tree CONFIGFLAGS="" - ubuntu-20.04	4m 8s
testinstall - JULIA=yes CONFIGFLAGS="--enable-debug --disable-Werror" - ubuntu-20.04	4m 37s
testmockpkg testinstall - - windows-2019	5m 43s
Send Slack notification on status change	1s
	1h 25m 37s

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