perf(codegen): a truthiness test asks a loop region for no Number lane

[proggeramlug]

Fixes the #10495 own3 regression that #11795 introduced.

Cause

#11795 admits a loop region whose Number reads (R) fall on non-identity lanes and tests their values on every guard. Both of the region's R collectors counted a value that is only tested for truthiness as a Number operand: number_operand_reads, and the accumulator value flow region_number_flow_reads. In a += (o.$L ? 1 : 0) + (o.$d ? 1 : 0) + … they requested R for o.$L, a string. The learned word carried the value test, which failed on every iteration, so the loop paid the guard and then the generic path (227 to 246 instructions per op).

Fix

A conditional's test and a ! operand are not Number operands. The conditional's arms are still values. Both collectors skip the test and the ! operand.

Results (instructions per op)

row	morning	main	this PR
#10495 own3	227	246	227

Real workloads (n=5, median instructions:u; main = 5b06d69)

workload	main instr	this PR	delta	full GCs main/PR	RSS KB main/PR	binary bytes main/PR
tsc (transpile x3)	184,902,302,770	184,880,958,985	-0.01%	244/244	323,052/324,368	182,782,336/182,782,336
zod x5000	19,831,886,486	19,826,300,154	-0.03%	0/0	59,396/58,828	24,440,056/24,440,056
qs parse_nested	32,985,522,956	32,986,164,020	+0.00%	0/0	60,144/60,372	27,301,072/27,288,720
commander parse_argv	8,912,561,402	8,912,263,665	-0.00%	0/0	57,528/56,448	34,203,080/34,203,080

Outputs are identical to main's in every run.

Verification

• New codegen test a_truthiness_test_requests_no_number_lane: R mask 0 and no value test for h += o.x ? 1 : 0 and h += !o.x ? 1 : 0. Control: h += n ? o.x : 0 still requests R.
• perry-codegen (all) passed. Gap suite (1254 files) compared with main: 0 regressions. fmt: clean.

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📥 Commits

Reviewing files that changed from the base of the PR and between 07e50b1 and 2a61df7.

📒 Files selected for processing (4)

• changelog.d/PENDING-regfix-region-truthiness.md
• crates/perry-codegen/src/collectors/ptr_shape_numeric.rs
• crates/perry-codegen/src/expr/region_loop_tests.rs
• crates/perry-codegen/src/stmt/region_loop/plan.rs

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