ARM: Change longjmp() to not use a post-sp-modification fixup
ARM: Change longjmp() to not use a post-sp-modification fixup

This is in preparation for changing the validator so that it doesn't
allow sp to be temporarily set to point outside the sandbox address
space (the bottom 1GB).

This also shortens the code!

This change also makes the "/* Bundle */" comments correct.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3144
TEST="./pnacl/build.sh libs-support-native arm" + run_thread_suspension_test

Review URL: https://codereview.chromium.org/11312256

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@10279 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

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