add custom pragma support for var and let symbols (#9582)

* add custom pragma support for var and let symbols
* updated changelog for custom pragmas on var and let symbols
* add oldast switch for backwards compatibility

changelog.md

@@ -23,7 +23,8 @@
 - The undocumented ``#? strongSpaces`` parsing mode has been removed.
 - The `not` operator is now always a unary operator, this means that code like
   ``assert not isFalse(3)`` compiles.
-
+- `getImpl` on a `var` or `let` symbol will now return the full `IdentDefs`
+  tree from the symbol declaration instead of just the initializer portion.
 
 #### Breaking changes in the standard library
 
@@ -133,8 +134,9 @@ proc enumToString*(enums: openArray[enum]): string =
   the `gcsafe` pragma block.
 - added os.getCurrentProcessId()
 - User defined pragmas are now allowed in the pragma blocks
-- Pragma blocks are now longer eliminated from the typed AST tree to preserve
+- Pragma blocks are no longer eliminated from the typed AST tree to preserve
   pragmas for further analysis by macros
+- Custom pragmas are now supported for `var` and `let` symbols.
 
 ### Language changes
 
@@ -143,10 +145,10 @@ proc enumToString*(enums: openArray[enum]): string =
   it's more recognizable and allows tools like github to recognize it as Nim,
   see [#9647](https://github.com/nim-lang/Nim/issues/9647).
   The previous extension will continue to work.
-- Pragma syntax is now consistent. Previous syntax where type pragmas did not 
+- Pragma syntax is now consistent. Previous syntax where type pragmas did not
   follow the type name is now deprecated. Also pragma before generic parameter
   list is deprecated to be consistent with how pragmas are used with a proc. See
-  [#8514](https://github.com/nim-lang/Nim/issues/8514) and 
+  [#8514](https://github.com/nim-lang/Nim/issues/8514) and
   [#1872](https://github.com/nim-lang/Nim/issues/1872) for further details.