make Base.return_types interface similar to code_typed

Especially, it should be more consistent with the other reflection
utilities defined in reflection.jl if the optional 
`interp::AbstractInterpreter`
argument is passed as keyword one.

Author: aviatesk

base/reflection.jl

@@ -1291,11 +1291,12 @@ function code_typed_opaque_closure(@nospecialize(closure::Core.OpaqueClosure);
     end
 end
 
-function return_types(@nospecialize(f), @nospecialize(types=default_tt(f)), interp=Core.Compiler.NativeInterpreter())
+function return_types(@nospecialize(f), @nospecialize(types=default_tt(f));
+                      world = get_world_counter(),
+                      interp = Core.Compiler.NativeInterpreter(world))
     ccall(:jl_is_in_pure_context, Bool, ()) && error("code reflection cannot be used from generated functions")
     types = to_tuple_type(types)
     rt = []
-    world = get_world_counter()
     for match in _methods(f, types, -1, world)::Vector
         match = match::Core.MethodMatch
         meth = func_for_method_checked(match.method, types, match.sparams)

test/compiler/AbstractInterpreter.jl

@@ -42,30 +42,30 @@ import Base.Experimental: @MethodTable, @overlay
 CC.method_table(interp::MTOverlayInterp) = CC.OverlayMethodTable(CC.get_world_counter(interp), OverlayedMT)
 
 @overlay OverlayedMT sin(x::Float64) = 1
-@test Base.return_types((Int,), MTOverlayInterp()) do x
+@test Base.return_types((Int,); interp=MTOverlayInterp()) do x
     sin(x)
 end == Any[Int]
-@test Base.return_types((Any,), MTOverlayInterp()) do x
+@test Base.return_types((Any,); interp=MTOverlayInterp()) do x
     Base.@invoke sin(x::Float64)
 end == Any[Int]
 
 # fallback to the internal method table
-@test Base.return_types((Int,), MTOverlayInterp()) do x
+@test Base.return_types((Int,); interp=MTOverlayInterp()) do x
     cos(x)
 end == Any[Float64]
-@test Base.return_types((Any,), MTOverlayInterp()) do x
+@test Base.return_types((Any,); interp=MTOverlayInterp()) do x
     Base.@invoke cos(x::Float64)
 end == Any[Float64]
 
 # not fully covered overlay method match
 overlay_match(::Any) = nothing
 @overlay OverlayedMT overlay_match(::Int) = missing
-@test Base.return_types((Any,), MTOverlayInterp()) do x
+@test Base.return_types((Any,); interp=MTOverlayInterp()) do x
     overlay_match(x)
 end == Any[Union{Nothing,Missing}]
 
 # partial pure/concrete evaluation
-@test Base.return_types((), MTOverlayInterp()) do
+@test Base.return_types(; interp=MTOverlayInterp()) do
     isbitstype(Int) ? nothing : missing
 end == Any[Nothing]
 Base.@assume_effects :terminates_globally function issue41694(x)
@@ -77,6 +77,6 @@ Base.@assume_effects :terminates_globally function issue41694(x)
     end
     return res
 end
-@test Base.return_types((), MTOverlayInterp()) do
+@test Base.return_types(; interp=MTOverlayInterp()) do
     issue41694(3) == 6 ? nothing : missing
 end == Any[Nothing]