RFR: 8314265: Fix -Wconversion warnings in miscellaneous runtime code

[Coleen Phillimore]

Fix MaxElementPrintSize and casts. Also fixed miscellaneous -Wconversion warnings in runtime code.  This is the last one I'm going to do for runtime for a while.
Tested with tier1-4.

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Commit messages:
 - Use parse_integer instead of strtol with a cast.
 - Unset Wconversion
 - Fix elf files.
 - Revert utf8.cpp
 - Fix -Wconversion warnings in misc runtime code.
 - Fix command line flag and metaspace.  Another 4 files.

Changes: https://git.openjdk.org/jdk/pull/15233/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15233&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8314265
  Stats: 93 lines in 34 files changed: 4 ins; 2 del; 87 mod
  Patch: https://git.openjdk.org/jdk/pull/15233.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15233/head:pull/15233

PR: https://git.openjdk.org/jdk/pull/15233