Small string fixes for encoding compatibility issues #377

Job	Run time
ruby-versions / Generate Ruby versions	2s
windows-latest 2.7	3m 35s
windows-latest 3.0	1m 59s
windows-latest 3.1	1m 30s
windows-latest 3.2	1m 50s
windows-latest 3.3	1m 55s
windows-latest 3.4	2m 55s
windows-latest jruby-head	2m 44s
windows-latest mingw	1m 38s
windows-latest mswin	1m 6s
	19m 14s

Provide feedback