Fixes 8616 (#8617)

* Don't leave dangling forward references to types

Fixes #8616

* Add a test case for #8616

compiler/ccgstmts.nim

@@ -1130,8 +1130,8 @@ proc genAsgn(p: BProc, e: PNode, fastAsgn: bool) =
       patchAsgnStmtListExpr(patchedTree, e, ri)
       genStmts(p, patchedTree)
       return
-
     var a: TLoc
+    discard getTypeDesc(p.module, le.typ.skipTypes(skipPtrs))
     if le.kind in {nkDerefExpr, nkHiddenDeref}:
       genDeref(p, le, a, enforceDeref=true)
     else:

tests/ccgbugs/pkg8616/rtarray.nim

@@ -0,0 +1,2 @@
+proc head*[T](pp: var array[1,T]): var T =
+  result = pp[0]

tests/ccgbugs/pkg8616/scheduler.nim

@@ -0,0 +1,10 @@
+import rtarray
+
+type
+  T = tuple[x:int]
+
+var
+  arr: array[1,T]
+
+proc init*() =
+  discard head(arr)

tests/ccgbugs/t8616.nim

@@ -0,0 +1,4 @@
+import pkg8616 / scheduler
+
+when isMainModule:
+  init()