Partially revert "Replace tuple with record in Cextcall (#10)"

This partially reverts commit 2cd07e6.

Revert the changes to ocaml/testsuite/tools

Author: gretay-js

ocaml/testsuite/tools/parsecmm.mly

@@ -220,12 +220,7 @@ expr:
   | LPAREN APPLY location expr exprlist machtype RPAREN
                 { Cop(Capply $6, $4 :: List.rev $5, debuginfo ?loc:$3 ()) }
   | LPAREN EXTCALL STRING exprlist machtype RPAREN
-               {Cop(Cextcall {name=$3; ret=$5; alloc=false;
-                              builtin=false;
-                              effects=Arbitrary_effects;
-                              coeffects=Has_coeffects;
-                              label_after=None},
-                     List.rev $4, debuginfo ())}
+               {Cop(Cextcall($3, $5, false, None), List.rev $4, debuginfo ())}
   | LPAREN ALLOC exprlist RPAREN { Cop(Calloc, List.rev $3, debuginfo ()) }
   | LPAREN SUBF expr RPAREN { Cop(Cnegf, [$3], debuginfo ()) }
   | LPAREN SUBF expr expr RPAREN { Cop(Csubf, [$3; $4], debuginfo ()) }