inference: look for :terminate_globally override in backedge termin…

…ation check (#44106)

Now we can "fix" #41694:
```julia
Base.@assume_effects :terminates_globally function issue41694(x)
    res = 1
    1 < x < 20 || throw("bad")
    while x > 1
        res *= x
        x -= 1
    end
    return res
end
@test fully_eliminated() do
    issue41694(2)
end
```

base/compiler/abstractinterpretation.jl

@@ -1878,7 +1878,7 @@ function abstract_eval_statement(interp::AbstractInterpreter, @nospecialize(e),
  effects.consistent ? ALWAYS_TRUE : TRISTATE_UNKNOWN,
  effects.effect_free ? ALWAYS_TRUE : TRISTATE_UNKNOWN,
  effects.nothrow ? ALWAYS_TRUE : TRISTATE_UNKNOWN,
- effects.terminates ? ALWAYS_TRUE : TRISTATE_UNKNOWN,
+ effects.terminates_globally ? ALWAYS_TRUE : TRISTATE_UNKNOWN,
  ))
  else
  tristate_merge!(sv, Effects())
@@ -2052,8 +2052,11 @@ end
 function handle_control_backedge!(frame::InferenceState, from::Int, to::Int)
  if from > to
  def = frame.linfo.def
- if isa(def, Method) && decode_effects_override(def.purity).terminates_locally
- return nothing
+ if isa(def, Method)
+ effects = decode_effects_override(def.purity)
+ if effects.terminates_globally || effects.terminates_locally
+ return nothing
+ end
  end
  tristate_merge!(frame, Effects(EFFECTS_TOTAL, terminates=TRISTATE_UNKNOWN))
  end

base/compiler/types.jl

@@ -89,7 +89,7 @@ struct EffectsOverride
  consistent::Bool
  effect_free::Bool
  nothrow::Bool
- terminates::Bool
+ terminates_globally::Bool
  terminates_locally::Bool
 end
 
@@ -98,7 +98,7 @@ function encode_effects_override(eo::EffectsOverride)
  eo.consistent && (e |= 0x01)
  eo.effect_free && (e |= 0x02)
  eo.nothrow && (e |= 0x04)
- eo.terminates && (e |= 0x08)
+ eo.terminates_globally && (e |= 0x08)
  eo.terminates_locally && (e |= 0x10)
  e
 end

test/compiler/inline.jl

@@ -1055,3 +1055,17 @@ function f_call_invoke_callback(f::FCallback)
  return nothing
 end
 @test !fully_eliminated(f_call_invoke_callback, Tuple{FCallback})
+
+# https://github.com/JuliaLang/julia/issues/41694
+Base.@assume_effects :terminates_globally function issue41694(x)
+ res = 1
+ 1 < x < 20 || throw("bad")
+ while x > 1
+ res *= x
+ x -= 1
+ end
+ return res
+end
+@test fully_eliminated() do
+ issue41694(2)
+end