spec: remove more stale implementation notes (google#342)

doc/spec.md

@@ -4231,7 +4231,7 @@ applications to mimic the Bazel dialect more closely. Our goal is
 eventually to eliminate all such differences on a case-by-case basis.
 See [Starlark spec issue 20](https://github.com/bazelbuild/starlark/issues/20).
 
-* String interpolation supports the `[ixXc]` conversions.
+* String interpolation supports the `[ioxXc]` conversions.
 * String elements are bytes.
 * Non-ASCII strings are encoded using UTF-8.
 * Strings support hex byte escapes.

starlark/testdata/string.star

@@ -412,9 +412,6 @@ assert.fails(lambda: sorted("abc"), "got string, want iterable")  # sorted
 assert.fails(lambda: [].extend("bc"), "got string, want iterable")  # list.extend
 assert.fails(lambda: ",".join("abc"), "got string, want iterable")  # string.join
 assert.fails(lambda: dict(["ab"]), "not iterable .*string")  # dict
-
-# The Java implementation does not correctly reject the following cases:
-# (See Google Issue b/34385336)
 assert.fails(for_string, "string value is not iterable")  # for loop
 assert.fails(lambda: [x for x in "abc"], "string value is not iterable")  # comprehension
 assert.fails(lambda: all("abc"), "got string, want iterable")  # all