prover: len/cross-array/fixed-new/affine proofs; keep facts past call loops

Rebased the prover WIP onto main. lafact_keep restores undirtied allocation
facts even when the loop body might free (so a later touch() no longer drops
every length fact). proven_p uses ptr_still so an outer call keeps the check.
entry_fact still supplies the size for the "might free" explain reason.
bounds_prover.zc and explain_prover.zc land with test.sh coverage.

1 files changed, 9 insertions, 0 deletions

diff --git a/tests/programs/explain_prover.expected b/tests/programs/explain_prover.expected
new file mode 100644
index 0000000..c43c72d
--- /dev/null
+++ b/tests/programs/explain_prover.expected
@@ -0,0 +1,9 @@
+{"version":1}
+{"file":"<eval>","line":18,"col":42,"end_line":18,"end_col":45,"fn":"main","kind":"index","loop_depth":1,"reason":"bound-not-invariant","fix":"the loop body changes the index, the bound or the array, takes an address or makes a closure; keep them fixed inside the loop"}
+{"file":"<eval>","line":22,"col":51,"end_line":22,"end_col":54,"fn":"main","kind":"index","loop_depth":1,"reason":"index-not-len-derived","fix":"bound the loop with len() of the array, or with a constant no larger than its length"}
+{"file":"<eval>","line":26,"col":62,"end_line":26,"end_col":65,"fn":"main","kind":"pointer","loop_depth":2,"reason":"pointer-may-be-freed","fix":"the loop body calls something that might free or resize the block; move the call out of the loop"}
+{"file":"<eval>","line":27,"col":71,"end_line":27,"end_col":74,"fn":"main","kind":"pointer","loop_depth":2,"reason":"index-not-len-derived","fix":"bound the loop with len() of the array, or with a constant no larger than its length"}
+{"file":"<eval>","line":30,"col":46,"end_line":30,"end_col":49,"fn":"main","kind":"index","loop_depth":1,"reason":"index-not-len-derived","fix":"bound the loop with len() of the array, or with a constant no larger than its length"}
+{"file":"<eval>","line":34,"col":81,"end_line":34,"end_col":92,"fn":"main","kind":"index","loop_depth":2,"reason":"index-not-loop-variable","fix":"index with the variable of a loop for (i = 0; i < bound; i++), or mark the code unbounded if the index is known to be in range"}
+{"file":"<eval>","line":35,"col":70,"end_line":35,"end_col":81,"fn":"main","kind":"index","loop_depth":2,"reason":"index-not-loop-variable","fix":"index with the variable of a loop for (i = 0; i < bound; i++), or mark the code unbounded if the index is known to be in range"}
+{"file":"<eval>","line":36,"col":59,"end_line":36,"end_col":70,"fn":"main","kind":"index","loop_depth":2,"reason":"index-not-loop-variable","fix":"index with the variable of a loop for (i = 0; i < bound; i++), or mark the code unbounded if the index is known to be in range"}