Enable goto-cc to build and link Xen

[tautschnig]

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[tautschnig]

Marking do-not-merge as it is an unhealthy mix of different bugfixes. Yet it makes a Xen build succeed when using the following script:

#!/usr/bin/env bash
# this should reproduce the compilation problem with goto-gcc on upstream Xen

set -e

# tested on Ubuntu 14.04
sudo apt-get install bcc python-dev uuid-dev libaio-dev libyajl-dev

# get upstream xen, move to staging branch
if [ ! -d xen.git ]
then
  git clone git://xenbits.xen.org/xen.git xen.git
fi
cd xen.git
git checkout staging

# the following patch is required to work around embedded-C problems
#--- a/xen/Makefile
#+++ b/xen/Makefile
#@@ -189,7 +189,7 @@ include/asm-$(TARGET_ARCH)/asm-offsets.h: arch/$(TARGET_ARCH)/asm-offsets.s
#          echo "#ifndef __ASM_OFFSETS_H__"; \
#          echo "#define __ASM_OFFSETS_H__"; \
#          echo ""; \
#-         sed -rne "/==>/{s:.*==>(.*)<==.*:\1:; s: [\$$#]: :; p;}"; \
#+         sed -rne "/^[^#].*==>/{s:.*==>(.*)<==.*:\1:; s: [\$$#]: :; p;}"; \
#          echo ""; \
#          echo "#endif") <$< >$@
#

# install goto-gcc as gcc replacement
mkdir -p hooks
pushd hooks
echo "goto-gcc --native-compiler /usr/bin/gcc \"\$@\"" > gcc
echo "goto-bcc --native-compiler /usr/bin/bcc \"\$@\"" > bcc
echo "goto-g++ --native-compiler /usr/bin/g++ \"\$@\"" > g++
echo "goto-as86 --native-assembler /usr/bin/as86 \"\$@\"" > as86
chmod u+x *
export PATH=$(pwd):$PATH
popd

export PATH=$HOME/cbmc-github.git/src/goto-cc:$HOME/cbmc-github.git/scripts:$PATH

# (re)build xen with goto-gcc as gcc replacement
./configure LD=goto-ld
make xen -j 1 LD=goto-ld

[tautschnig]

Rebased against latest develop to reduce the patch set to those that are specific to Xen (and thus retitled). Keeping do-not-merge as the linker hack is dubious and a full set-up for an integration test should be included (and that test should be performed) -- that test should just use the script posted above.

[tautschnig]

Closing as #2557 contains all the necessary fixes.