Remove duplicate vr_values::extract_range_builtin code.

Remove duplicate vr_values::extract_range_builtin code.

Now that we know the vr_values and ranger versions are in sync, it is
safe to remove the vr_values version and just call the ranger one.

I am leaving the UBSAN bits in place since they make use of
relationals which are still not implemented in the ranger.

gcc/ChangeLog:

	* vr-values.c (vr_values::extract_range_builtin): Rename to...
	(vr_values::extract_range_from_ubsan_builtin): ...this.
	Remove everything but UBSAN code.
	(vr_values::extract_range_basic): Call ranger version for
	everything except UBSAN built-ins.
	* vr-values.h (class vr_values): Rename extract_range_builtin to
	extract_range_from_ubsan_builtin.