issue deprecation warning on use of google/ headers
added tc_malloc_skip_new_handler

This is port of corresponding chromium change at:
https://codereview.chromium.org/55333002/

Basic idea is that sometimes apps that use tc_set_new_mode in order to
have C++ out-of-memory handler catch OOMs in malloc, need to invoke
usual malloc that returns 0 on OOM.

That new API is exactly for that. It'll always return NULL on OOM even
if tc_new_mode is set to true.
issue-614: use tc_memalign in ReallocAfterMemalloc test

Because some OSes lack plain memalign. And we really need to test our
implementation which is always available via tc_malloc.
Fixed the use of addr2line to discover the separator symbol.

In systems where addr2line has a version greater than 2.22 pprof fails
in discover the separator symbol (_fini). This patch identifies if
addr2line can find the symbol, otherwise pprof uses objdump to recover
a address that addr2line's newer versions can recognize as the separator
function.
Fixed the way that pprof packed profile data in BE.

pprof was writing profile data in a way that only works for little-endian
files, this patch verifies if the system is big-endian and writes packed
data correctly.
Fixed issues with heap checker on PPC64 LE.

Fixed the wrapper for the syscall sys_clone and the test for heap
checker on PPC64 LE. Both use the ODP structure, which is only
used on BE architectures.
VDSOsupport cleanup

This patch cleans up unused VDSO getcpu racking from VDSOsupport class,
since the code is not used anywhere in gperftools and symbol name is not
architecture independent.
PowerPC: stacktrace function refactor and fixes

This patch fixes the stacktrace creating when the function is
interrupted by a signal. For Linux, the vDSO signal trampoline symbol is
compared against LR from stack backchain and handled different in that
case (since the signal trampoline layout a different stack frame).

Because of this extensive change the PowerPC stacktrace code has now
been refactored to split in Linux and Darwin specific codes.
eliminated CheckIfKernelSupportsTLS

We don't care about pre-2.6.0 kernels anymore. So we can assume that
if compile time check worked, then at runtime it'll work.
avoid recursion in backtrace()
extended low_level_alloc

By adding ability to customize pages allocator
implemented emergency malloc