4.2.91
Refresh the test suite framework implementation.
Add test suite support to Windows
* tests/scripts/misc/fopen-fail: [SV 42390] Increase test timeout.
* Added the test suite to the main distribution.
* tests/scripts/misc/general3: Add more tests for SHELL/.SHELLFLAGS
* tests/run_make_tests.pl: Create $scriptsuffix for Windows/VMS.
* makeint.h (STOP_SET): [SV 40371] Cast to unsigned char.