JIT doesn't trace exec()-generated functions called from hot loops

When a hot loop calls functions generated via exec(), the loop body gets traced but the callees don't. Each callee is individually cold (called ~60 times), but the call site is hot (5,000+ calls total across different callees).

Concrete case: tinygrad generates ~5,000 pattern matching functions at startup via exec(). They're called from a tight loop:

for _, match, _ in pats:
    if (ret := match(uop, ctx)) is not None: return ret

PYTHON_JIT=1 on 3.14.4 produces no improvement. The specializer works (LOAD_ATTR_SLOT fires correctly), but the JIT never compiles the callees.

Related: faster-cpython/ideas#738, #118093 (tier 2 entry at function calls).

It would be useful to either trace through exec()-generated callees at hot call sites, or detect aggregate hotness across callees sharing a call site.

Linked PRs

• gh-149575

Start by reproducing the tinygrad pattern-matching loop with PYTHON_JIT=1 on Python 3.14.4, focusing on the exec()-generated callees and their shared hot call site. Compare the specializer's LOAD_ATTR_SLOT behavior with whether the callees are compiled; done means the reported hot-call workload shows JIT improvement through the generated functions.