Adjust to upcoming julia#54341 (#292)

The feature check is done using julia#53849 (which is itself a bit
of an experiment), so the idea is to merge/tag this before the base
PR is merged to prevent breakage on julia master.

Author: Keno

src/codegen/reverse.jl

@@ -111,9 +111,17 @@ function diffract_ir!(ir, ci, meth, sparams::Core.SimpleVector, nargs::Int, N::I
         if nc % 2 == 1
             opaque_ci.slotnames = Symbol[Symbol("#self#"), :Δ]
             opaque_ci.slotflags = UInt8[0, 0]
+            if isdefined(Base, :__has_internal_change) && Base.__has_internal_change(v"1.12-alpha", :codeinfonargs)
+                opaque_ci.nargs = 2
+                opaque_ci.isva = false
+            end
         else
             opaque_ci.slotnames = [Symbol("#oc#"), ci.slotnames...]
             opaque_ci.slotflags = UInt8[0, ci.slotflags...]
+            if isdefined(Base, :__has_internal_change) && Base.__has_internal_change(v"1.12-alpha", :codeinfonargs)
+                opaque_ci.nargs = 1 + ci.nargs
+                opaque_ci.isva = ci.isva
+            end
         end
         @static if VERSION ≥ v"1.12.0-DEV.173"
             opaque_ci.debuginfo = ci.debuginfo

src/stage1/recurse.jl

@@ -314,5 +314,10 @@ function optic_transform!(ci::CodeInfo, mi::MethodInstance, nargs::Int, N::Int)
     ci.method_for_inference_limit_heuristics = meth
     ci.edges = MethodInstance[mi]
 
+    if isdefined(Base, :__has_internal_change) && Base.__has_internal_change(v"1.12-alpha", :codeinfonargs)
+        ci.nargs = 2
+        ci.isva = true
+    end
+
     return ci
 end

src/stage1/recurse_fwd.jl

@@ -210,6 +210,11 @@ function fwd_transform!(ci::CodeInfo, mi::MethodInstance, nargs::Int, N::Int, E)
     ci.method_for_inference_limit_heuristics = meth
     ci.edges = MethodInstance[mi]
 
+    if isdefined(Base, :__has_internal_change) && Base.__has_internal_change(v"1.12-alpha", :codeinfonargs)
+        ci.nargs = 2
+        ci.isva = true
+    end
+
     return ci
 end