RFR: 8267304: Bump global JTReg memory limit to 768m

[Igor Ignatyev]

On Tue, 18 May 2021 09:51:09 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> See the rationale in the RFE.
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `java/time/format/TestZoneTextPrinterParser.java` with aggressive GC options
>  - [x] Linux x86_64 fastdebug `jdk:tier1`
>  - [x] Linux x86_64 fastdebug `tier1`
>  - [x] Linux x86_64 fastdebug `tier2`
>  - [x] Linux x86_32 fastdebug `tier1`
>  - [x] Linux x86_32 fastdebug `tier2`

LGTM

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Marked as reviewed by iignatyev (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/4087