Fix wierd problems linking C programs which look for symbols in libstdc++.

Fix wierd problems linking C programs which look for symbols in libstdc++.
This was due to the 'assert' macro expanding into a function call on some
platforms which could throw.  The C++ compiler then added checks for the
exception specifications in these functions, which pulled in the C++ runtime.
This was bad, and the assertions can never fire (the library is now debugged)
so just remove them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9801 91177308-0d34-0410-b5e6-96231b3b80d8