Add JNA 3rd party library.
Stub native call ops.
Stub the NativeCall and CPointer REPRs.
Set correct argument signatures for native call ops.
Add JNA to build and runtime JARs.
First implementation of nqp::buildnativecall.
Move constants to enum from static final byte FOO.
Build NativeCallInstance.{arg_types,ret_type} in nqp::buildnativecall.
Basic call handling and converting between NQP and JNA types.

This means that we support int, num, str and cpointer as arguments and return
values, which in turn means that we pass the basic sanity tests in the NQP
test suite.
Run native call tests as part of the standard test target.
Merge branch 'master' into nativecall-jvm
Stub the CArray and CStr REPRs.

We need these to get NativeCall.pm6 to compile.
Stub nqp::nativecallrefresh.

Also needed to get NativeCall.pm6 to compile.
Lazy allocation of HashMap for  VMHash storage on JVM.
Merge pull request #134 from perl6/lazy-vmhash

Lazy allocation of HashMap for  VMHash storage on JVM.
nqp::iscont should not blow up over a null value.

This fixes a broken case of .clone that the subscripting changes in
Rakudo hit. Thus, this fixes a more general issue.
Normalize $*OS on Windows to be MSWin32.

Many things identify Windows in this way at present.
Parse _ in ** quantifier values.

Also sneak in a decent NYI error for the ** {...} case.
nqp::openpipe handling for Windows.
Make 02-pipes.t Windows-friendly.