7000: Store invocation site for eager macros r=edwin0cheng a=jonas-schievink
Fixes https://github.com/rust-analyzer/rust-analyzer/issues/6992
r? @edwin0cheng
I'm not sure if this is totally correct, it looks like we create **two** `EagerCallLoc`s per macro invocation, one for the arguments (?), and one for the actual macro call. I gave both the same `AstId`, hopefully that's correct.
Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>
493e29d713