RFR: 8280289: Enhance debug pp() command with NMT info [v2]

[Zhengyu Gu]

> JDK-8275320 enhanced NMT malloc header, provided ability to identify if a pointer points to a malloc'd memory. Further,  JDK-8277822 enabled NMT for debug builds.
> 
> This is a good opportunity to integrate NMT to debug pp() command to provide useful information collected by NMT. 
> 
> For example:
> 
> NMT=summary
> 
> (gdb) call pp(0x7f2d9803db70)
> "Executing pp"
> 0x00007f2d9803db70 malloc'd 1576 bytes by Internal
> 
> (gdb) call pp(0x00007f4300a20000)
> "Executing pp"
> 0x00007f4300a20000 in mmap'd memory region [0x00007f4300a20000 - 0x00007f4310000000] by GC
> 
> 
> NMT=detail
> 
> 
> (gdb) call pp(0x7f2d9803db70)
> "Executing pp"
> 0x00007f2d9803db70 malloc'd 1576 bytes by Internal
> [0x00007f2d9f1b784b] G1Arguments::create_heap()+0x1b
> [0x00007f2d9f98a855] universe_init()+0x85
> [0x00007f2d9f2e0a97] init_globals()+0x37
> [0x00007f2d9f960acb] Threads::create_vm(JavaVMInitArgs*, bool*)+0x3db
> 
> (gdb) call pp(0x00007f4300a20000)
> "Executing pp"
> 0x00007f4300a20000 in mmap'd memory region [0x00007f4300a20000 - 0x00007f4310000000] by GC
> [0x00007f433dc49c7f] reserve_memory(char*, unsigned long, unsigned long, int, bool)+0x17f
> [0x00007f433dc4cf0b] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x14b
> [0x00007f433dc4d527] ReservedSpace::initialize(unsigned long, unsigned long, unsigned long, char*, bool)+0x1c7
> [0x00007f433d949d40] ShenandoahHeap::initialize()+0x340

Zhengyu Gu has updated the pull request incrementally with one additional commit since the last revision:

  Thomas' comments

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7160/files
  - new: https://git.openjdk.java.net/jdk/pull/7160/files/789e69e0..65fcfd4d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7160&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7160&range=00-01

  Stats: 48 lines in 3 files changed: 15 ins; 8 del; 25 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7160.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7160/head:pull/7160

PR: https://git.openjdk.java.net/jdk/pull/7160