RFR: 8147012: Fix includes in internalVMTests.cpp

[Erik Helin]

Hi all,

this patch fixes the includes in
src/share/vm/utilities/internalVMTests.cpp - all test functions should be
declared using "forward declarations" [0] to ensure fast compilation and
also enable an better `run_unit_test` macro (this will be introduced in a
future patch).

The patch is touches quite a few files but it is easy to verify the
changes per file and internalVMTests.cpp.

Enhancement:
https://bugs.openjdk.java.net/browse/JDK-8147012

Webrev:
http://cr.openjdk.java.net/~ehelin/8147012/00/

Testing:
- Running `make test-hotspot-internal` locally on Linux x86-64
- JPRT

Thanks,
Erik

[0]: https://en.wikipedia.org/wiki/Forward_declaration