RFR: 8320781: Fix whitespace in j.l.Double and j.u.z.ZipInputStream @snippets

[Brian Burkhalter]

On Mon, 27 Nov 2023 16:17:14 GMT, Eirik Bjorsnos <duke at openjdk.org> wrote:

> Please review this trivial, formatting and documentation-only change which adds missing whitespace around a few `if` statements, `while` statements and assigments in `@snippet` code in `j.l.Double` and `j.u.z.ZipInputStream`.
> 
> While there are many similar issues in the OpenJDK code base, these were the only instances found in `@snippet` code in the API of `java.base`, so it could be worthwhile fixing. 
> 
> While updating the snippet in `ZipInputStream`, I took the liberty to also add `lang = "java"` since this seems more commonly included around the code base.

Marked as reviewed by bpb (Reviewer).

-------------

PR Review: https://git.openjdk.org/jdk/pull/16827#pullrequestreview-1751057799