Tests: switch off some RunCMake tests for broken libc on e2k

Some old OS Elbrus installations (e.g. 6.0.1) have libc that
tends to behave incorrectly in some rare cases. This prevents
some tests from being run correctly:
- RunCMake.Graphviz, test no_module_libs
- RunCMake.Syntax, test EscapeCharsDisallowed
These tests are now not run in case of such libc.
3 files changed