Fixes up dump_syms build on OS X so it works with ELF.

Adds elf.h header from glibc.
Updates dwarf2reader.cc so it isn't comparing a unique_ptr against NULL.
Moves from MacOS10.5 SDK to latest SDK for Xcode project.
Moves from using gcc to clang for dump_syms tests.
Disables warning about 'Missing Field In Structure Initializers' to temporarily work around https://bugs.chromium.org/p/google-breakpad/issues/detail?id=697.

With this patch all tests form dump_syms pass again using Xcode 7.3 on Mac OS X 10.11.

BUG= https://bugs.chromium.org/p/google-breakpad/issues/detail?id=696, https://bugs.chromium.org/p/google-breakpad/issues/detail?id=697
R=mark@chromium.org

Review URL: https://codereview.chromium.org/1970903002 .

1 files changed, 76 insertions, 0 deletions

diff --git a/src/third_party/glibc/README b/src/third_party/glibc/README
new file mode 100644
index 00000000..be687c7d
--- /dev/null
+++ b/src/third_party/glibc/README
@@ -0,0 +1,76 @@
+This directory contains the sources of the GNU C Library.
+See the file "version.h" for what release version you have.
+
+The GNU C Library is the standard system C library for all GNU systems,
+and is an important part of what makes up a GNU system.  It provides the
+system API for all programs written in C and C-compatible languages such
+as C++ and Objective C; the runtime facilities of other programming
+languages use the C library to access the underlying operating system.
+
+In GNU/Linux systems, the C library works with the Linux kernel to
+implement the operating system behavior seen by user applications.
+In GNU/Hurd systems, it works with a microkernel and Hurd servers.
+
+The GNU C Library implements much of the POSIX.1 functionality in the
+GNU/Hurd system, using configurations i[4567]86-*-gnu.  The current
+GNU/Hurd support requires out-of-tree patches that will eventually be
+incorporated into an official GNU C Library release.
+
+When working with Linux kernels, this version of the GNU C Library
+requires Linux kernel version 3.2 or later on all architectures except
+i[4567]86 and x86_64, where Linux kernel version 2.6.32 or later
+suffices.
+
+Also note that the shared version of the libgcc_s library must be
+installed for the pthread library to work correctly.
+
+The GNU C Library supports these configurations for using Linux kernels:
+
+	aarch64*-*-linux-gnu
+	alpha*-*-linux-gnu
+	arm-*-linux-gnueabi
+	hppa-*-linux-gnu	Not currently functional without patches.
+	i[4567]86-*-linux-gnu
+	x86_64-*-linux-gnu	Can build either x86_64 or x32
+	ia64-*-linux-gnu
+	m68k-*-linux-gnu
+	microblaze*-*-linux-gnu
+	mips-*-linux-gnu
+	mips64-*-linux-gnu
+	powerpc-*-linux-gnu	Hardware or software floating point, BE only.
+	powerpc64*-*-linux-gnu	Big-endian and little-endian.
+	s390-*-linux-gnu
+	s390x-*-linux-gnu
+	sh[34]-*-linux-gnu
+	sparc*-*-linux-gnu
+	sparc64*-*-linux-gnu
+	tilegx-*-linux-gnu
+	tilepro-*-linux-gnu
+
+If you are interested in doing a port, please contact the glibc
+maintainers; see http://www.gnu.org/software/libc/ for more
+information.
+
+See the file INSTALL to find out how to configure, build, and install
+the GNU C Library.  You might also consider reading the WWW pages for
+the C library at http://www.gnu.org/software/libc/.
+
+The GNU C Library is (almost) completely documented by the Texinfo manual
+found in the `manual/' subdirectory.  The manual is still being updated
+and contains some known errors and omissions; we regret that we do not
+have the resources to work on the manual as much as we would like.  For
+corrections to the manual, please file a bug in the `manual' component,
+following the bug-reporting instructions below.  Please be sure to check
+the manual in the current development sources to see if your problem has
+already been corrected.
+
+Please see http://www.gnu.org/software/libc/bugs.html for bug reporting
+information.  We are now using the Bugzilla system to track all bug reports.
+This web page gives detailed information on how to report bugs properly.
+
+The GNU C Library is free software.  See the file COPYING.LIB for copying
+conditions, and LICENSES for notices about a few contributions that require
+these additional notices to be distributed.  License copyright years may be
+listed using range notation, e.g., 1996-2015, indicating that every year in
+the range, inclusive, is a copyrightable year that would otherwise be listed
+individually.