Build IRT image with non-bitcode tools under bitcode=1
Build IRT image with non-bitcode tools under bitcode=1

Use the native newlib toolchain to build IRT images under bitcode=1 just as
we do under --nacl_glibc.  This makes the image that tests built under
bitcode=1 to use match the native-built image delivered into Chrome.

The irt.nexe built with pnacl tools does not work right because the pnacl
newlib is not yet built with -mtls-use-call (which the pnacl compiler does
not yet support).  Moreover, there will only be one canonical IRT image
built and we want the pnacl build to test pnacl-built nexes against that
one rather than one built differently.

BUG=http://code.google.com/p/nativeclient/issues/detail?id=1889
TEST=irt.nexe comes out identical with and without bitcode=1

R=jvoung@google.com

Review URL: http://codereview.chromium.org/7116001

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@5568 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client