Support for stmtListExpr in parser after major keywords. Scaled down version. (#10852)

* Support for stmtListExpr in parser after major keywords
* fixes #4035

changelog.md

@@ -29,6 +29,16 @@
 
 - `getImpl` on a `var` or `let` symbol will now return the full `IdentDefs`
   tree from the symbol declaration instead of just the initializer portion.
+- it is now possible to use statement list expressions after keywords with
+  indentation: raise, return, discard, yield. This helps parsing code produced 
+  by Nim template expansion where stmtListExpr can appear in place of any expression.
+  Example:
+```nim
+  raise 
+    var e = new(Exception)
+    e.msg = "My Exception msg"
+    e
+```
 
 - To use multi-methods, explicit `--multimethods:on` is now needed.