enable PIE for dynamically linked Linux host executables

Compile all host programs for Android with -fPIE and -pie. This
enables PIE (Position Independent Executables), which helps
protect these applications from exploitation due to memory
management bugs.

Note: PIE *static* executables are not supported at this time. darwin
and windows are also not supported.

Change-Id: I67c1be297711ea23064c349f97ebd02eef3eff09
Fix regex for finding symbol data.

The new output of debuggerd removed a space between the #00 and the rest
of the line. The regex is very restrictive, so fixing it to handle the new
output.

Change-Id: I5259ae1e56a351608b330dfd858a2021e6d89358
Enable NX protections

Add -Wa,--noexecstack and -Wl,-z,noexecstack as default
flags when compiling host-side applications.  This enables
NX protections, which prevent code from executing on the
stack or heap.  NX protections make exploiting memory
corruption issues more challenging and is an important
security feature.

Change-Id: Iae580abe887e01f9029ec2a4e0fc0aae496724a4
Add FORCE_BUILD_RS_COMPAT option.

This enables the .so libraries to be built for apps using the
RenderScript support library. Traditionally, we trim these .so
files from full platform builds.

Change-Id: I6f8e9b8d2b671338d3d5a5ac0bfcc60fd448688b
Add a "reverse AUX hack" for ARM.

MIPS and x86 are almost completely switched over to uapi-only. ARM is still
currently old-only. A cleanup of the uapi headers over the weekend means
that the uapi-only <linux/kexec.h> is now in the right place, which will break
the ARM build unless the ARM build also looks in the uapi headers if it can't
find an old header.

Change-Id: Ie7a53ef2122b43cdef64b71d7b36a8381992a461