Add error reporter for inlined quotes

[nicolasstucki]

No description provided.

[OlivierBlanvillain]

What about using exceptions instead?

else throw new QuoteExpansionError("foo cannot be called with false")

The compiler could catch this particular one and forward the message to it's reporter. The downside compared to what you did in this PR it wouldn't cover warning, but it would also be easier to document.

[nicolasstucki]

That is the solution in the first commit (reverted in the third commit). It did not cover warnings or multiple errors. Though with exceptions it was simpler and more intuitive for the users IMO. On the other hand, the current implementation is more flexible.
WDYT? @OlivierBlanvillain, @biboudis @liufengyun

[OlivierBlanvillain]

I think having a single error and no distinction between errors and warnings shouldn't be a problem, @implicitNotFound and @ambiguiousImplicits works this way seem to be sufficient.

scala> import annotation.{implicitNotFound => inf}
import annotation.{implicitNotFound=>inf}

scala> @inf("A") trait A
defined trait A

scala> @inf("B") trait B
defined trait B

scala> def foo()(implicit a: A, b: B) = ()
foo: ()(implicit a: A, implicit b: B)Unit

scala> foo()
<console>:14: error: A
       foo()
          ^

[odersky]

I also tend to favor exceptions. Gives a simpler API for macros.

[nicolasstucki]

Then I will rework that version

[nicolasstucki]

Done