absint: merge const_prop_enabled into bail_out_const_call (#52921)

Both of these interfaces have nearly identical roles. Considering the
simplicity in the codebase and the possible overloads by external
abstract interpreters, it seems more sensible to unify them into one
interface. Also tweaks remarks a bit.

base/compiler/abstractinterpretation.jl

@@ -814,7 +814,7 @@ end
 function abstract_call_method_with_const_args(interp::AbstractInterpreter,
     result::MethodCallResult, @nospecialize(f), arginfo::ArgInfo, si::StmtInfo,
     match::MethodMatch, sv::AbsIntState, invokecall::Union{Nothing,InvokeCall}=nothing)
-    if !const_prop_enabled(interp, match, sv) || bail_out_const_call(interp, result, si, sv)
+    if bail_out_const_call(interp, result, si, match, sv)
         return nothing
     end
     eligibility = concrete_eval_eligible(interp, f, result, arginfo, sv)
@@ -847,26 +847,26 @@ function abstract_call_method_with_const_args(interp::AbstractInterpreter,
     return const_prop_call(interp, mi, result, arginfo, sv, concrete_eval_result)
 end
 
-function const_prop_enabled(interp::AbstractInterpreter, match::MethodMatch, sv::AbsIntState)
+function bail_out_const_call(interp::AbstractInterpreter, result::MethodCallResult,
+                             si::StmtInfo, match::MethodMatch, sv::AbsIntState)
     if !InferenceParams(interp).ipo_constant_propagation
         add_remark!(interp, sv, "[constprop] Disabled by parameter")
-        return false
+        return true
     end
     if is_no_constprop(match.method)
         add_remark!(interp, sv, "[constprop] Disabled by method parameter")
-        return false
+        return true
     end
-    return true
-end
-
-function bail_out_const_call(interp::AbstractInterpreter, result::MethodCallResult,
-                             si::StmtInfo, sv::AbsIntState)
     if is_removable_if_unused(result.effects)
-        if isa(result.rt, Const) || call_result_unused(si)
+        if isa(result.rt, Const)
             add_remark!(interp, sv, "[constprop] No more information to be gained (const)")
             return true
+        elseif call_result_unused(si)
+            add_remark!(interp, sv, "[constprop] No more information to be gained (unused result)")
+            return true
         end
-    elseif result.rt === Bottom
+    end
+    if result.rt === Bottom
         if is_terminates(result.effects) && is_effect_free(result.effects)
             # In the future, we may want to add `&& isa(result.exct, Const)` to
             # the list of conditions here, but currently, our effect system isn't