RFR: 8378319: Obsolete the MaxRAM flag

[Joel Sikström]

Hello,

This PR obsoletes the MaxRAM flag after being deprecated in JDK26. Removing the flag from the arguments-parsing code is straightforward, but is more complicated in the documentation and several tests using the flag.

For the documentation I've opted to use the term "available memory to the JVM process" consistently instead, which I've repurposed from the now removed description of the MaxRAM flag.

There are several tests using the MaxRAM flag because of its type (uint64_t). For those tests I've replaced it with either `ErrorLogTimeout` or `StringDeduplicationHashSeed`. Since we don't have any "unlimited/unbound" product uint64_t flags, I've used `StringDeduplicationHashSeed` for places requiring an "unlimited/unbound" flag, and made sure that `-XX:+UnlockDiagnosticVMOptions` is present.

There are three jtreg tests that have been using MaxRAM to "simulate" being on a machine with more RAM than might be available and I've had to come up with a new approach for all three.

test/hotspot/jtreg/gc/arguments/TestMaxRAMFlags.java (renamed to TestMaxRAMPercentage.java)
test/hotspot/jtreg/gc/arguments/TestUseCompressedOopsFlagsWithUlimit.java
test/hotspot/jtreg/gc/g1/TestRegionAlignment.java


Perhaps the most controversial change is for TestMaxPercentage.java (renamed from testMaxRAMFlags.java), which is only run for machines with more RAM than the required maxcoopheapsize + a bit of headroom, so we can test all scenarios.

Testing:
* I've run all tests that I've changed locally in both release and fastdebug on Mac+Linux.
* Oracle's tier1-4

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Commit messages:
 - 8378319: Obsolete the MaxRAM flag

Changes: https://git.openjdk.org/jdk/pull/29838/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29838&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378319
  Stats: 347 lines in 11 files changed: 152 ins; 163 del; 32 mod
  Patch: https://git.openjdk.org/jdk/pull/29838.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29838/head:pull/29838

PR: https://git.openjdk.org/jdk/pull/29838