[CompilerDevTools] Properly handle builtins in with_new_compiler (#58074)

Author: Keno

Compiler/extras/CompilerDevTools/src/CompilerDevTools.jl

@@ -54,10 +54,8 @@ function Compiler.transform_result_for_cache(interp::SplitCacheInterp, result::C
         isexpr(stmt, :call) || continue
         f = stmt.args[1]
         f === override && continue
-        if isa(f, GlobalRef)
-            T = widenconst(argextype(f, ir))
-            T <: Core.Builtin && continue
-        end
+        T = widenconst(argextype(f, ir))
+        T <: Core.Builtin && continue
         insert!(stmt.args, 1, override)
         insert!(stmt.args, 3, interp.owner)
     end
@@ -67,6 +65,10 @@ end
 with_new_compiler(f, args...; owner::SplitCacheOwner = SplitCacheOwner()) = with_new_compiler(f, owner, args...)
 
 function with_new_compiler(f, owner::SplitCacheOwner, args...)
+    # We try to avoid introducing `with_new_compiler` in the first place,
+    # but if we can't see the type, it's still possible to end up with a
+    # builtin here - simply forward to the ordinary builtin call.
+    isa(f, Core.Builtin) && return f(args...)
     mi = lookup_method_instance(f, args...)
     new_compiler_ci = Core.OptimizedGenerics.CompilerPlugins.typeinf(
         owner, mi, Compiler.SOURCE_MODE_ABI

Compiler/extras/CompilerDevTools/test/runtests.jl

@@ -17,4 +17,8 @@ using CompilerDevTools: lookup_method_instance, SplitCacheInterp
   # required extra work to be cached under the same cache owner.
   mi = lookup_method_instance(do_work, 1, 2)
   @test haskey(cache, mi)
+
+  # Should not error with a builtin whose type we do not know
+  f_unknown_builtin() = Base.compilerbarrier(:type, isa)(1, Int)
+  with_new_compiler(f_unknown_builtin, interp.owner) === true
 end;