Conflicts:
	libc/fd.cc

  __xstat change: obsoleted by upstream
  open64(): moved to fs/vfs/main.c

When we aligned the sizes for mmap(), we neglected to clear memory between
the end of the read data and the beginning of anonymous memory.  If a variable
sat there, it would not be initialized correctly.

Could be better, but waiting for vfs revamp anyway.

This seems to break the actual jvm execution for some reason.

Also based on prex code.

Various changes to fit into the OSv environment.  This also includes
a ramfs in-memory full filesystem.  Bootfs is rewritten as a simple
unpacker into ramfs, and the fs class is modified to wrap the VFS
instead of being an abstract subclass.

Using the recently commited strncmp broke the VFS path lookup.

On a release build, the compiler hoists the computation of current() until
after the wrmsr() which changes the TLS base, corrupting it.

Insert a barrier to fix.

Start with a simple compiler barrier.

Harmless.

Unlike most glibc data types, FILE is not opaque - it is defined as _IO_FILE
in libio.h and some glibc inlines actually use it.  So we must use the same
structure.  Do this by subclassing _IO_FILE.

Unbreaks mode=release build.

PT_GNU_EH_FRAME segments are contained within PT_LOAD segments, and
so need not be loaded.  Moreover, when we load a segment, we align
it to page boundaries; this overwrites previous contents.  Does
serious damage with small objects (like tst-dir.so) - overwriting
the main function.

Fix by ignoring EH_FRAME segments (libunwind will later re-discover
them when iterating over the objects's phdrs).

* 'master' of github.com:/avikivity/osv:
  bootfs: add some jars for the jvm
  bootfs: switch to  more traditional file layout
  elf: reduce debug noise
  README: document 'osv syms'
  mempool: fix corruption with almost-page-sized objects

Mirror the jre file layout closely, otherwise it gets confused.

When we free the last object in a page, we free the page itself, removing
it from the pool's page list.  However, pages with no free objects are not
present on the free page list, causing corruption.

The only condition this can happen is if there is exactly one object on a
page; so it's simultaneously the last allocated and the last freed object.

* 'master' of github.com:/avikivity/osv:
  mkbootfs: remove errant print
  build: quiet down mkbootfs invocation
  scripts: support multiple objects in running image
  elf: store object list in an area easily accessible to the debugger
  printf: implement zero fill
  libc: import qsort from freebsd

 - add git submodule init
 - use the right flag for autoreconf

Since we're loading multiple objects, we need to load symbol tables for all
of them.  The base addresses are no longer static (esp. after we started
loading mulitple payloads, so we need to read them from the image).

A new command is added for this: 'osv syms'.  It will try to locate symbol
tables for anything that has been loaded at this stage.

Since we're loading many objects, we need to make them accessible to the
debugger so it can load symbol tables.

as in "%016lx".