Generalize hash table literals and subtypes of symbol.

Closes PR 11670.

collects/tests/racket/benchmarks/shootout/typed/chameneos.rktl

@@ -88,7 +88,7 @@
          [meeting-ch : MeetingChannel (make-channel)])
     (place meeting-ch n)
     (newline)
-    (for ([init inits])
+    (for: ([init : Color inits])
       (printf " ~a" init)
       (creature init meeting-ch result-ch))
     (newline)

collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt

@@ -872,7 +872,8 @@
    (tc-l #"foo" -Bytes)
    [tc-l () (-val null)]
    [tc-l (3 . 4) (-pair -PositiveFixnum -PositiveFixnum)]
-   [tc-l #hash((1 . 2) (3 . 4)) (make-Hashtable -PositiveFixnum -PositiveFixnum)])
+   [tc-l #hash((1 . 2) (3 . 4)) (make-Hashtable -Integer -Integer)]
+   [tc-l #hasheq((a . q) (b . w)) (make-Hashtable -Symbol -Symbol)])
   ))
 
 

collects/typed-scheme/typecheck/tc-expr-unit.rkt

@@ -96,7 +96,7 @@
      (let* ([h (syntax-e #'i)]
             [ks (hash-map h (lambda (x y) (tc-literal x)))]
             [vs (hash-map h (lambda (x y) (tc-literal y)))])
-       (make-Hashtable (apply Un ks) (apply Un vs)))]
+       (make-Hashtable (generalize (apply Un ks)) (generalize (apply Un vs))))]
     [(a . b) (-pair (tc-literal #'a) (tc-literal #'b))]
     [_ Univ]))
 

collects/typed-scheme/types/convenience.rkt

@@ -47,6 +47,7 @@
                t-new
                (exit t)))]
         [(ListDots: t bound) (-lst (substitute Univ bound t))]
+        [(? (lambda (t) (subtype t -Symbol))) -Symbol]
         [_ (exit t)]))))