Add temporary hack to -Wuninitialize to create a separate CFG (for C++ code) that...

Add temporary hack to -Wuninitialize to create a separate CFG (for C++ code) that doesn't include implicit dtors.

Implicit dtors confuse the ad hoc path-sensitivity of UninitializedValuesV2.cpp.  This isn't
the ideal solution, as it will directly impact compile time, but should significantly reduce
the noise of -Wuninitialized on some code bases.

This immediately "fixes" the false positive reported in PR 9063, although this
isn't the right fix in the long run.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124667 91177308-0d34-0410-b5e6-96231b3b80d8