The same specific function will (eventually) be emitted as part of
lowering multiple different source files, so don't give them unique
external linkage.
`IRBuilderBase::SetInsertPoint` weirdly replaces our debug location with
one copied from the new insertion point, so undo its damage after
calling it.
Also included: a couple of cleanups I made while tracking this down.
Emitting definitions in check. This resolves the crash in lowering which
necessitated definitions be emitted.
Some of the test changes need further review.
Resolve instruction id depending on the context from which a function is
called.
Calling a function in a function context that does not have a definition
emitted before reaching lowering will cause a crash. This needs a change
in check/eval layer.
Richard Smith
Alina Sbirlea