Adds fold::symbolic::parseFunctionContracts(fd, ctx) — reads
RawCommentList for a function decl and returns the param indices
proven non-null by `/*@ requires <param> != null */` clauses.
SecurityWalker calls applyInitialFunctionContracts before walkCFG,
so within-function derefs see the contract via the existing
isDefinitelyNonNull pre-filter.
Grammar v1: bare `<ident> != null|NULL|nullptr`. Multi-line and
multi-clause supported. Unrecognised shapes are silently rejected
so future grammar growth doesn't break existing files.
applyHostToolchain now passes -fparse-all-comments. Without it
clang's lexer drops ordinary block comments before they reach the
AST, so the contract syntax can't ride along on `/*` ... `*/`.
Scope: suppresses within-function derefs on contracted params.
Does NOT suppress call-site findings — that needs CrossTUCache
integration so callee CalleeProperties carry the precondition.
Filed as a follow-up on matrix row C8.
Refs docs/library-expansion-matrix.md row C8.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
