Don't inline ambiguous method calls

This will centralize our handling in the C code, since we have to handle it there anyway

Author: timholy

base/inference.jl

@@ -2281,6 +2281,17 @@ function inlineable(f::ANY, ft::ANY, e::Expr, atypes::Vector{Any}, sv::Inference
     metharg = meth[1]::Type
     methsp = meth[2]
     method = meth[3]::Method
+    ambig = method.ambig
+    if ambig != nothing
+        # do the arguments apply?
+        for entry in ambig
+            modsig = Tuple{entry.sig.parameters[2:end]...}
+            modatypes = Tuple{atypes[2:end]...}
+            if typeintersect(modsig, modatypes) != Union{}
+                return NF
+            end
+        end
+    end
     if isa(f, widenconst(ft)) && !method.isstaged && method.lambda_template.pure && (isType(e.typ) || isa(e.typ,Const))
         # check if any arguments aren't effect_free and need to be kept around
         stmts = Any[]

test/ambiguous.jl

@@ -1,9 +1,9 @@
 # DO NOT CHANGE LINE NUMBERS BELOW
-@noinline foo(x, y) = 1
-@noinline foo(x::Integer, y) = 2
-@noinline foo(x, y::Integer) = 3
-@noinline foo(x::Int, y::Int) = 4
-@noinline foo(x::Number, y) = 5
+foo(x, y) = 1
+foo(x::Integer, y) = 2
+foo(x, y::Integer) = 3
+foo(x::Int, y::Int) = 4
+foo(x::Number, y) = 5
 # END OF LINE NUMBER SENSITIVITY
 
 ambigs = Any[[], [3], [2,5], [], [3]]
@@ -28,3 +28,7 @@ end
 @test foo(3, 4) == 4
 @test_throws ErrorException foo(0x03, 4)
 @test_throws ErrorException foo(0x03, 4)  # test that not inserted into cache
+
+# Ensure it still works with potential inlining
+bar(x, y) = foo(x, y)
+@test_throws ErrorException bar(0x03, 4)