IR framework does not handle client VM builds correctly

There are some problems when using the IR framework with a client VM build:
- The IR framework currently only bails out of IR matching if C2 is excluded by command line flags. However, when running an IR JTreg test with a client VM build, IR matching fails when not specifically adding @requires vm.compiler2.enabled to exclude the test.
- @Test and @ForceCompile do not work correctly and throw an exception due to an incompatible compilation level.
- Some internal framework tests fail.