Allow std/macros.params to work with nnkProcTy (#19563)

* Allow std/macros.params to work with nnkProcTy

* Add tests for proc params & pragma

lib/core/macros.nim

@@ -1271,11 +1271,18 @@ proc `name=`*(someProc: NimNode; val: NimNode) =
   else: someProc[0] = val
 
 proc params*(someProc: NimNode): NimNode =
+  if someProc.kind == nnkProcTy:
+    someProc[0]
+  else:
     someProc.expectRoutine
-  result = someProc[3]
+    someProc[3]
+
 proc `params=`* (someProc: NimNode; params: NimNode) =
-  someProc.expectRoutine
   expectKind(params, nnkFormalParams)
+  if someProc.kind == nnkProcTy:
+    someProc[0] = params
+  else:
+    someProc.expectRoutine
     someProc[3] = params
 
 proc pragma*(someProc: NimNode): NimNode =

tests/macros/tprochelpers.nim

@@ -0,0 +1,22 @@
+import std/macros
+import stdtest/testutils
+
+macro test1(prc: untyped): untyped =
+  assertAll:
+    prc.params.len == 2
+    prc.params[1].len == 4
+    prc.pragma.len == 2
+
+  prc.params = nnkFormalParams.newTree(
+    ident("int")
+  )
+  prc.pragma = newEmptyNode()
+
+  assertAll:
+    prc.params.len == 1
+    prc.pragma.len == 0
+  prc
+
+proc test(a, b: int): int {.gcsafe, raises: [], test1.} = 5
+
+type hello = proc(a, b: int): int {.gcsafe, raises: [], test1.}