Finer-grained constant cache invalidation (take 2)

This commit reintroduces finer-grained constant cache invalidation.
After 8008fb7 got merged, it was causing issues on token-threaded
builds (such as on Windows).

The issue was that when you're iterating through instruction sequences
and using the translator functions to get back the instruction structs,
you're either using `rb_vm_insn_null_translator` or
`rb_vm_insn_addr2insn2` depending if it's a direct-threading build.
`rb_vm_insn_addr2insn2` does some normalization to always return to
you the non-trace version of whatever instruction you're looking at.
`rb_vm_insn_null_translator` does not do that normalization.

This means that when you're looping through the instructions if you're
trying to do an opcode comparison, it can change depending on the type
of threading that you're using. This can be very confusing. So, this
commit creates a new translator function
`rb_vm_insn_normalizing_translator` to always return the non-trace
version so that opcode comparisons don't have to worry about different
configurations.

[Feature #18589]

1 files changed, 3 insertions, 0 deletions

diff --git a/iseq.h b/iseq.h
index f90b0be7ab..a7d542fa09 100644
--- a/iseq.h
+++ b/iseq.h
@@ -182,6 +182,9 @@ void rb_iseq_build_from_ary(rb_iseq_t *iseq, VALUE misc,
 void rb_iseq_mark_insn_storage(struct iseq_compile_data_storage *arena);
 
 /* iseq.c */
+typedef bool rb_iseq_each_i(VALUE *code, VALUE insn, size_t index, void *data);
+void rb_iseq_each(const rb_iseq_t *iseq, size_t start_index, rb_iseq_each_i iterator, void *data);
+
 VALUE rb_iseq_load(VALUE data, VALUE parent, VALUE opt);
 VALUE rb_iseq_parameters(const rb_iseq_t *iseq, int is_proc);
 unsigned int rb_iseq_line_no(const rb_iseq_t *iseq, size_t pos);