fixes #10838 (#10841)

* fixes #10838
* reject func in types instead
* trigger tests

compiler/parser.nim

@@ -1109,6 +1109,8 @@ proc parseProcExpr(p: var TParser; isExpr: bool; kind: TNodeKind): PNode =
     result = newNodeI(nkProcTy, info)
     if hasSignature:
       addSon(result, params)
+      if kind == nkFuncDef:
+        parMessage(p, "func keyword is not allowed in type descriptions, use proc with {.noSideEffect.} pragma instead")
       addSon(result, pragmas)
 
 proc isExprStart(p: TParser): bool =

tests/proc/tfunc_type.nim

@@ -0,0 +1,14 @@
+
+discard """
+  errmsg: "func keyword is not allowed in type descriptions, use proc with {.noSideEffect.} pragma instead"
+"""
+
+type
+  MyObject = object
+    fn: func(a: int): int
+
+proc myproc(a: int): int =
+  echo "bla"
+  result = a
+
+var x = MyObject(fn: myproc)