Summary: G1ElasticHeap to support heap shrink/expansion in runtime

Test Plan:
test/elastic-heap/

Reviewers:

Issue:
https://github.com/alibaba/dragonwell8/issues/46

CR:
https://github.com/alibaba/dragonwell8_hotspot/pull/12

Test Plan: existing test cases

Reviewed-by: shiyue, kuaiwei

Issue: https://github.com/alibaba/dragonwell8/issues/52

Summary:
  change build script and to code to support windows platform

Test Plan:
  existing test cases

Reviewers:
  shiyue, chuansheng

Issue:
  https://aone.alibaba-inc.com/task/22514166

CR:

Summary:
  Port jwarmup to dragonwell 8u hotspot

ref T19299187

Test Plan:
test/hotspot/jtreg/jwarmup/Issue11272598.java
test/hotspot/jtreg/jwarmup/TestDisableNCE.java
test/hotspot/jtreg/jwarmup/TestNotDeoptJITMethod.sh
test/hotspot/jtreg/jwarmup/issue9780156.sh
test/hotspot/jtreg/jwarmup/TestEagerCompilation.java
test/hotspot/jtreg/jwarmup/TestNotifyDeopt.sh
test/hotspot/jtreg/jwarmup/TestCheckIfCompilationIsComplete.sh
test/hotspot/jtreg/jwarmup/TestFlagAssertion.java
test/hotspot/jtreg/jwarmup/TestReadLogfile.java
test/hotspot/jtreg/jwarmup/TestClassInitChain.java
test/hotspot/jtreg/jwarmup/TestLogFlush.java
test/hotspot/jtreg/jwarmup/TestRecordNullMethodCounter.java
test/hotspot/jtreg/jwarmup/TestThrowInitializaitonException.java
test/hotspot/jtreg/jwarmup/TestDisableMethodData.sh
test/hotspot/jtreg/jwarmup/TestMethodRecorder.java
test/hotspot/jtreg/jwarmup/TestTieredCompilationInRecording.sh

Reviewers: 传胜, 三红, yumin.qi

Reviewed By: 传胜, 三红

Subscribers: 麦庶

Differential Revision: https://aone.alibaba-inc.com/code/D852146

Reviewers: 效山, 芳玺, 传胜, 三红, yumin.qi

Reviewed By: 三红, 芳玺, 效山, 卓仁

Differential Revision: https://aone.alibaba-inc.com/code/D815657

Summary: Prepare Zero build for backport of JDK-8062808.
Reviewed-by: sgehwolf

Reviewed-by: clanger, andrew

Summary: Compile with -O3 and relevant C flags as for fdlibm.
Reviewed-by: andrew

Reviewed-by: erikj, dholmes

Summary: Remove Linux kernel version check as very unlikely a kernel older than 2.4 will be used.
Reviewed-by: erikj

Summary: Introduce alignment-safe Copy::conjoint_swap and JVM_CopySwapMemory
Reviewed-by: mikael, dholmes

Reviewed-by: erikj

Reviewed-by: tbell

Summary: Only produce those files if STRIP_POLICY != no_strip
Reviewed-by: erikj

Summary: Only add .gnu_debuglink sections when there is some stripping done.
Reviewed-by: erikj, dholmes

Reviewed-by: dholmes, erikj

Reviewed-by: dholmes, erikj

8073139: PPC64: User-visible arch directory and os.arch value on ppc64le cause issues with Java tooling
Reviewed-by: erikj, goetz, dholmes

Reviewed-by: erikj

Summary: Generate debug info for assembler files as needed.
Reviewed-by: erikj

Reviewed-by: tbell

Reviewed-by: tbell

Reviewed-by: dsamersoff, erikj

Reviewed-by: ihse, mikael, brutisso

Reviewed-by: ihse, mikael, brutisso

Reviewed-by: tbell, mikael

Reviewed-by: tbell, mikael

Reviewed-by: asaha

Reviewed-by: dcubed, mikael

Reviewed-by: dcubed, mikael

Reviewed-by: dholmes, dcubed

Reviewed-by: dholmes

Reviewed-by: dholmes

Reviewed-by: katleman

Reviewed-by: dholmes

Reviewed-by: dholmes

Reviewed-by: dholmes

Reviewed-by: dholmes

Reviewed-by: dholmes

Reviewed-by: katleman