change define_maps! syntax to include fn preceding $name

[durka]

In this macro:

rust/src/librustc/ty/maps.rs

Lines 566 to 569 in faf477a

	macro_rules! define_maps {
	(<$tcx:tt>
	$($(#[$attr:meta])*
	[$($modifiers:tt)*] $name:ident: $node:ident($K:ty) -> $V:ty,)*) => {

This will make it easier to grep for a symbol without knowing whether it is a regular function or a query.

Also consider changing the name from define_maps! to define_queries! (and the module name as well?).

As discussed on IRC with @eddyb and @nikomatsakis.

[durka]

There is this $modifiers thing, but it seems to be always empty in the current usage of define_maps!. Is it an artifact of history that should be removed?

[nikomatsakis]

@durka my expectation is still that we will use it, that's why it's not been removed yet, but I'm also ok removing it and adding it back later when we want it.