RFR: 8296776: Stop using mtNone as marker for CHeap allocations in GrowableArray

[Stefan Karlsson]

Today we use mtNone to denote that a GrowableArray should *NOT* be backed by a CHeap allocated array.

I've gotten feedback that it would probably be good to limit the usage of mtNone, and at some point maybe completely remove it.

This patch takes a small step to remove mtNone from the GrowableArray. What's left is only asserts to forbid that value. Those asserts will be trivial to remove when/if mtNone is removed.

Just like in the proposed patch to make MEMFLAGS non-optional in CHeapBitMap (see JDK-[JDK-8296774](https://bugs.openjdk.org/browse/JDK-8296774)), I have thrown around the parameter order for GrowableArray. When looking at the changes to the usages of CHeap-backed GrowableArrays it becomes apparent that all of these usages where forced to provide a value for the initial capacity. When MEMFLAGS move to the front, we can now skip having to figure an initial capacity.

-------------

Commit messages:
 - 8296776: Stop using mtNone as marker for CHeap allocations in GrowableArray

Changes: https://git.openjdk.org/jdk/pull/11086/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11086&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296776
  Stats: 157 lines in 61 files changed: 25 ins; 5 del; 127 mod
  Patch: https://git.openjdk.org/jdk/pull/11086.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11086/head:pull/11086

PR: https://git.openjdk.org/jdk/pull/11086