RFR: 8253261: Disable CDS full module graph until JDK-8253081 is fixed

[Calvin Cheung]

On Wed, 16 Sep 2020 20:38:20 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> Please review this trivial patch.
> 
> [JDK-8244778](https://bugs.openjdk.java.net/browse/JDK-8244778) (Archive full module graph in CDS) is causing failures
> in GC ([JDK-8253081](https://bugs.openjdk.java.net/browse/JDK-8253081))
> This patch disables the *use* of the CDS module graph at run time, which seems to avoid the GC problems. The module
> graph is still being archived into CDS, but that seems to be harmless.

Looks good.

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Marked as reviewed by ccheung (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/213