macro.

This reverts commit 54ce8e1c.

functions

simple_logger)

need to be fixed)

internally they do nothing (gc doesnt move in zebu atm)

single defining has same behavior

handle. (whoever requires the handle manages its lifetime)

(cannot load this test as dylib, it would involve PIC code on linux)

global

1. see vm/vm_options.rs for usage and default values
2. added mu_fastimpl_new_with_opts under vm/api/api_impl/muvm.rs

Note: made two places in api implementation as unimplemented as
the instruction/type chnaged.

now

Also fixed a bug in FuncVer building.

Creaation and destruction of MuVM, MuCtx and MuIRBuilder. Now the
`mvm->new_context`, `ctx->new_ir_builder`, `ctx->close_context` and
`b->abort` works. MuVM can also be created via a top-level "C"-style
exported function `mu_fastimpl_new()` so that in theory, it can be used
in C programs.