llvm: Simplify translator

Replace 'llvm_context' with 'llvm_translator' and move the translation
loop into it.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
java: Generic translator

Convert the LLVM translator into a generic one so we can reuse
translate() across different backends.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
Convert DynASM backend to use generic translator

Signed-off-by: Pekka Enberg <penberg@kernel.org>
Add simple integer arithmetic operation tests

Signed-off-by: Pekka Enberg <penberg@kernel.org>