cpputest: Test failure with gcc 10.x in Linux

If you build cpputest with gcc 10.x on Debian Linux on amd64, you will get two test failures:

tests/MemoryOperatorOverloadTest.cpp:349: error: Failure in TEST(OutOfMemoryTestsForOperatorNew,
FailingNewArrayOperatorThrowsAnExceptionWhenUsingStdCppNewWithoutOverride)
        expected to throw std::bad_alloc
but threw nothing

.
tests/MemoryOperatorOverloadTest.cpp:344: error: Failure in TEST(OutOfMemoryTestsForOperatorNew,
FailingNewOperatorThrowsAnExceptionWhenUsingStdCppNewWithoutOverride)
        expected to throw std::bad_alloc
but threw nothing

Given that GCC 10.x will soon be the default, it would be nice to have fixes for those issues.

The full build log can be seen here: https://people.debian.org/~doko/logs/gcc10-20200225/cpputest_3.8-7_unstable_gcc10.log

This has been reported in Debian first: https://bugs.debian.org/957104