Produce .weak_def_can_be_hidden for some linkonce_odr values

With this patch llvm produces a weak_def_can_be_hidden for linkonce_odr
if they are also unnamed_addr or don't have their address taken.

There is not a lot of documentation about .weak_def_can_be_hidden, but
from the old discussion about linkonce_odr_auto_hide and the name of
the directive this looks correct: these symbols can be hidden.

Testing this with the ld64 in Xcode 5 linking clang reduces the number of
exported symbols from 21053 to 19049.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193718 91177308-0d34-0410-b5e6-96231b3b80d8
Add calls to doInitialization() and doFinalization() in verifyFunction()

The function verifyFunction() in lib/IR/Verifier.cpp misses some
calls. It creates a temporary FunctionPassManager that will run a
single Verifier pass. Unfortunately, FunctionPassManager is no
PassManager and does not call doInitialization() and doFinalization()
by itself. Verifier does important tasks in doInitialization() such as
collecting type information used to check DebugInfo metadata and
doFinalization() does some additional checks. Therefore these checks
were missed and debug info couldn't be verified at all, it just
crashed if the function had some.

verifyFunction() is currently not used in llvm unless -debug option is
enabled, and in unittests/IR/VerifierTest.cpp

VerifierTest had to be changed to create the function in a module from
which the type debug info can be collected.

Patch by Michael Kruse.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193719 91177308-0d34-0410-b5e6-96231b3b80d8
Teach scalarrepl about address spaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193720 91177308-0d34-0410-b5e6-96231b3b80d8