[dyncall] next shot at fixing the build on Strawberry Perl

Should work universally, but testing on OSX would be appreciated.
OSX 64 bit target for NativeCall
Remove stray blanks
Rolled QAST::Operations.add_hll_unbox calls into loop
Use .nqp extension consistently.
Add 3rdparty/asm from nqp-jvm-prep repo.
Move C code, ops and PMCs under src/vm/parrot/.
Update .gitignore.
ModuleLoader.nqp will be VM-specific.
Toss dead code.
Parrot QAST backed moves under src/vm/parrot.
Split out HLL::Backend from HLL::Compiler.
NQP Ops.nqp is also VM-specific.
Move stage0 into src/parrot/vm/.

The stage0 is inherently platform specific, since it's generated code.
Segregate Parrot-specific tests.
We'll need a Makefile per backend.
Stub ConfigureJVM.pl and Makefile-JVM.in.
Add JVM runtime support; get Makefile to build it.
Add a conditional compilation mechanism.

gen-cat.pl now takes an argument for the current backend, and handles
directives in the files it is processing related to VM-specific code.
Add an nqp::scgetdesc op.