Some CORE regression tests do not complete when CBMC is built with Glucose

[reuk]

Discovered on #1293.

Using the Glucose/CMake build of CBMC (enabled by passing -Dsat_impl=glucose when running the initial configure), some CORE regression tests appear not to complete:

• strings-smoke-tests/java_int_to_string/test2.desc
• strings-smoke-tests/java_int_to_string_with_radix/test_decimal.desc
• strings-smoke-tests/java_long_to_string/test1.desc

[tautschnig]

This doesn't seem to be a problem any longer. As of #5709 we use Glucose in one of our GitHub actions.