Move x/codegen/J9TreeEvaluator.cpp evaluators to i386/amd64

[0xdaryl]

There are some function implementations in the common x86 J9TreeEvaluator class that are ifdefed for 32-bit and 64-bit (e.g., [1] and [2], among others) which doesn't follow the idioms of extensible classes. These functions should be moved into appropriate architecture-specific files without ifdefs (i.e., a i386/codegen/J9TreeEvaluator.cpp and a amd64/codegen/J9TreeEvaluator.cpp). Neither of these files exist, so they will have to be created.

Sweep through x/codegen/J9TreeEvaluator.cpp and move evaluator functions ifdefed for an architecture.

[1]

openj9/runtime/compiler/x/codegen/J9TreeEvaluator.cpp

Line 968 in 7431737

#ifdef TR_TARGET_32BIT

[2]

openj9/runtime/compiler/x/codegen/J9TreeEvaluator.cpp

Line 13722 in 7431737

#ifdef TR_TARGET_64BIT