RFR: 8318296: Move Space::initialize to ContiguousSpace

[Thomas Schatzl]

On Tue, 17 Oct 2023 11:57:59 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Simple refactoring of moving methods to subclass. (`clear` is also moved, as it is called inside `initialize`.)

Lgtm.

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Marked as reviewed by tschatzl (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16219#pullrequestreview-1682680414