[dev.ssa] cmd/compile: PPC64, basic support for all calls and "miscellaneous"

[dev.ssa] cmd/compile: PPC64, basic support for all calls and "miscellaneous"

Added support for ClosureCall, DeferCall, InterCall
(GoCall not yet tested).

Added support for GetClosurePtr, IsNonNil, IsInBounds, IsSliceInBounds, NilCheck
(Convert and GetG not yet tested)

Still need to implement NilCheck optimizations.
Fixed move boolean constant, order of operands to subtract.

Updates #16010.

Change-Id: Ibe0f6a6e688df4396cd77de0e9095997e4ca8ed2
Reviewed-on: https://go-review.googlesource.com/25241
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>