test NEW instruction, also test thread transformation and worked around libmu library loading problem

add array sum test; add linked list reversal test; add simple test for new and thread transformation; refactor to allow compiling through C backend

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

going to test it with test_jit suite

1. grow/shrink frame size in the pro/epilogue. Note: though we removed
push/pop for unused callee saved registers, we still reserve frame space
for them. Because we generate spill on frame before we know exactly how
large a space is. The solution is to make spill locations patchable.
2. control flow will combine branches in switch instruction if they all
target the same destination.