PmCheck: Long-distance information for LocalBinds (#18626)
Now desugarLocalBind
(formerly desugarLet
) reasons about
- The
abs_binds
of anAbsBinds
post type-checking, or -
FunBind
s that- Have no pattern matches (so which aren't functions)
- Have a singleton match group with a single GRHS
- (which may have guards)
And desugars to PmLet
LYG-style guards. Since GRHSs are no longer
denoted simply by NonEmpty PmGRHS
, but also need to carry a [PmGrd]
for the PmLet
s from LocalBind
s, I added PmGRHSs
to capture that.
There's a regression test in T18626
. Fixes #18626 (closed).