fixes #18769 (#18790)

compiler/semgnrc.nim

@@ -107,6 +107,12 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
     else:
       result = n
     onUse(n.info, s)
+  of skEnumField:
+    if overloadableEnums in c.features:
+      result = symChoice(c, n, s, scOpen)
+    else:
+      result = newSymNode(s, n.info)
+      onUse(n.info, s)
   else:
     result = newSymNode(s, n.info)
     onUse(n.info, s)
@@ -407,7 +413,7 @@ proc semGenericStmt(c: PContext, n: PNode,
         a[^1] = semGenericStmt(c, a[^1], flags, ctx)
         for j in 0..<a.len-2:
           addTempDecl(c, getIdentNode(c, a[j]), varKind)
-      else: 
+      else:
         illFormedAst(a, c.config)
   of nkGenericParams:
     for i in 0..<n.len:

tests/enum/toverloadable_enums.nim

@@ -1,6 +1,7 @@
 discard """
   output: '''B
-0'''
+0
+E2-B'''
 joinable: false
 """
 
@@ -75,3 +76,11 @@ block: # https://github.com/nim-lang/RFCs/issues/8
   doAssert x == 0
   doAssert hA3 == 1
   doAssert hA4 == 1
+
+# bug #18769
+proc g3[T](x: T, e: E2): int =
+  case e
+  of value1: echo "E2-A"        # Error: type mismatch: got 'E1' for 'value1' but expected 'E2 = enum'
+  of value2: echo "E2-B"
+
+let v5 = g3(99, E2.value2)