intel/compiler: Use linear allocator in various passes

Part of my on-going exploration to use more/better the linear allocator we have in util. This is a set of "easy" changes to use linear allocator in a few backend passes. Plus a couple of small related patches found along the way.

Note: some of the original patches moved to other MRs.

Together those changes will also improve compilation time in some cases. Here's a few fossil-db in my system (TGL):

// Rise of the Tomb Raider (n=13)
Difference at 95.0% confidence
	-0.25 +/- 0.016372
	-0.784778% +/- 0.0513934%
	(Student's t, pooled s = 0.0202231)

// Cyberpunk 2077 (n=13)
Difference at 95.0% confidence
	-6.49 +/- 0.0877311
	-2.99527% +/- 0.0404898%
	(Student's t, pooled s = 0.108368)

// Assassins Creed Odissey (n=27)
Difference at 95.0% confidence
	-0.0888889 +/- 0.00721278
	-0.513842% +/- 0.041695%
	(Student's t, pooled s = 0.0132045)

// Batman Arkham City (n=7)
Difference at 95.0% confidence
	-4.59 +/- 0.373906
	-0.862956% +/- 0.0702972%
	(Student's t, pooled s = 0.321025)

// Borderlands 3 (n=27)
Difference at 95.0% confidence
	-0.104815 +/- 0.00516644
	-1.04757% +/- 0.0516358%
	(Student's t, pooled s = 0.00945826)

// Total War Warhammer 3 (n=13)
Difference at 95.0% confidence
	-0.353846 +/- 0.0291462
	-0.314474% +/- 0.0259031%
	(Student's t, pooled s = 0.0360021)

Old results from a rebased version

// Rise of the Tomb Raider (n=13)
Difference at 95.0% confidence
	-0.224615 +/- 0.0146091
	-0.64702% +/- 0.0420824%
	(Student's t, pooled s = 0.0180455)

// Cyberpunk 2077 (n=13)
Difference at 95.0% confidence
	-2.37308 +/- 0.0426958
	-1.59946% +/- 0.028777%
	(Student's t, pooled s = 0.0527391)

// Assassins Creed (n=13)
Difference at 95.0% confidence
	-0.0746154 +/- 0.0109807
	-0.398259% +/- 0.0586096%
	(Student's t, pooled s = 0.0135637)

// Batman Arkham City (n=7)
Difference at 95.0% confidence
	-5.76857 +/- 0.248418
	-1.00421% +/- 0.0432453%
	(Student's t, pooled s = 0.213285)

// Borderlands 3 (n=13)
Difference at 95.0% confidence
	-0.0669231 +/- 0.0060804
	-0.619526% +/- 0.056288%
	(Student's t, pooled s = 0.00751068)

Older results from when the MR were posted

// Rise of the Tomb Raider (N=7)
Difference at 95.0% confidence
	-0.27 +/- 0.0129599
	-0.898588% +/- 0.0431317%

// Cyberpunk 2077 (N=9)
Difference at 95.0% confidence
	-2.63 +/- 0.20035
	-2.20831% +/- 0.168227%

// Assassins Creed Odyssey (N=22)
Difference at 95.0% confidence
	-0.0577273 +/- 0.00810855
	-0.392946% +/- 0.0551943%

// Batman Arkham City (N=5)
Difference at 95.0% confidence
	-6.176 +/- 0.564221
	-1.16742% +/- 0.106652%