phi-opt: Disable parts of it for -Og

phi-opt: Disable parts of it for -Og

While working on the cselim limited part of phiopt, I noticed
that the debugging experience for -Og case would cause jumping
execution in some cases. So this disables the store and operation
factoring parts for -Og since those 2 can cause the line information
of the debugging to be off.

Bootstrapped and tested on x86_64-linux-gnu.

gcc/ChangeLog:

	* tree-ssa-phiopt.cc (pass_phiopt::execute): Disable
	cselim-limited and factor out operations for -Og.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>