Code validation and IR verification improvements (#52844)

Author: maleadt

base/compiler/ssair/verify.jl

@@ -2,7 +2,8 @@
 
 function maybe_show_ir(ir::IRCode)
     if isdefined(Core, :Main)
-        invokelatest(Core.Main.Base.display, ir)
+        # ensure we use I/O that does not yield, as this gets called during compilation
+        invokelatest(Core.Main.Base.show, Core.stdout, "text/plain", ir)
     end
 end
 

base/compiler/validation.jl

@@ -253,7 +253,7 @@ end
 
 function is_valid_rvalue(@nospecialize(x))
     is_valid_argument(x) && return true
-    if isa(x, Expr) && x.head in (:new, :splatnew, :the_exception, :isdefined, :call, :invoke, :invoke_modify, :foreigncall, :cfunction, :gc_preserve_begin, :copyast)
+    if isa(x, Expr) && x.head in (:new, :splatnew, :the_exception, :isdefined, :call, :invoke, :invoke_modify, :foreigncall, :cfunction, :gc_preserve_begin, :copyast, :new_opaque_closure)
         return true
     end
     return false