Quick backend: rename target-specific #defines
Another step towards a single compiler. The #include build mechanism
relies on macros with the same name to take on different values for
our various targets. This CL prepends a target-specific string
(and exposes some needed by common code as functions rather than #defines).
Macros and #defines still available for use from target-dependent code,
but functions added for target independent use. For example,
rRET0 for Arm becomes rARM_RET0 in target-dependent code, and
targetRegister(kRet0) in target-independent code.
No logic changes, other than adding functions to return previously #defined
values. As of this CL, the primary target includes, xxxLIR.h, have no
34 files changed