RFR: JDK-8292071: NMT: move MallocHeader to its own header and inline header checks

[Ioi Lam]

On Tue, 9 Aug 2022 05:40:27 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> MallocHeader should be moved into its own header in preparation for further NMT changes.
> 
> Also, malloc header check routines - that are called on every free and realloc - should be inlined.
> 
> This is a plain code move. The classes were not changed, apart from making some of the functions inline, and fixing includes.

LGTM.

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Marked as reviewed by iklam (Reviewer).

PR: https://git.openjdk.org/jdk/pull/9801