vmError::controlled_crash should be #ifdef ASSERT and move tests to gtest

vmError::controlled_crash and the supporting infrastructure is defined within an #ifndef PRODUCT block. But much of what it does involves stuff that is #ifdef ASSERT. And the tests that use this mechanism, such as ErrorHandler.java, all @requires vm.debug == true.

Instead of being #ifndef PRODUCT, controlled_crash should be #ifdef ASSERT.

Also controlled_crash() has a set of specific asserts that it tests and these asserts should be in a gtest instead. This change should fix the string output with ExecuteUnitTests to match what is in the hs_err_pid file. eg:

# assert(how == 0) failed: test assert

rather than just "assert failed: test assert".