RFR: 8255495: Support CDS Archived Heap for uncompressed oops

[Calvin Cheung]

This proposed change adds support for uncompressed oops for CDS archived heap. It is needed
for supporting archived heap for ZGC in the future. For now, only G1GC is supported with this change.
During dump time with compressed oops disabled, the MaxHeapSize is set to 4GB. This is to ensure
the offset of any object in the heap from the bottom of the heap is always a 32-bit integer.

Passed CI tiers 1 - 4 and hs-tier7-rt tests.

Preliminary HelloWorld startup perf. improvement:

instr delta =    -68813432    -49.7140%
time  delta =      -14.720 ms -20.3599%

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

Commit messages:
 - fix a linux-x86 build issue
 - 8255495: Support CDS Archived Heap for uncompressed oops

Changes: https://git.openjdk.java.net/jdk/pull/7223/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7223&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255495
  Stats: 220 lines in 12 files changed: 163 ins; 6 del; 51 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7223.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7223/head:pull/7223

PR: https://git.openjdk.java.net/jdk/pull/7223