Don't reject types directly on AST (#19407)

Instead of rejecting type expressions based on node kind,
evaluate the expression as a type.
This is already the behavior for call results, and it has its own error
for non-types, which is the same error you would normally get
with 2 words swapped.

compiler/semtypes.nim

@@ -1993,8 +1993,10 @@ proc semTypeNode(c: PContext, n: PNode, prev: PType): PType =
   of nkStmtListType: result = semStmtListType(c, n, prev)
   of nkBlockType: result = semBlockType(c, n, prev)
   else:
-    localError(c.config, n.info, "type expected, but got: " & renderTree(n))
+    result = semTypeExpr(c, n, prev)
-    result = newOrPrevType(tyError, prev, c)
+    when false:
+      localError(c.config, n.info, "type expected, but got: " & renderTree(n))
+      result = newOrPrevType(tyError, prev, c)
   n.typ = result
   dec c.inTypeContext
 

tests/types/tnontype.nim

@@ -0,0 +1,9 @@
+discard """
+  errormsg: "expected type, but got: 3"
+"""
+
+type
+  Foo = (block:
+    int)
+  
+  Bar = 3