uninits related to C++ exceptions

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on February 23, 2014 19:11:43_

C++ code using a try/catch on Mac built with:
# c++ -v
Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn)

Has many uninits like these:

Dr. Memory version 1.6.179

Error `#1`: UNINITIALIZED READ: reading 0xbff82690-0xbff82698 8 byte(s)
#0 libunwind.dylib!unw_init_local
#1 libunwind.dylib!_Unwind_RaiseException
#2 libc++abi.dylib!__cxa_throw
#3 Triangle::Triangle [./utilities.h:15]
#4 EquilateralTriangle::EquilateralTriangle [./utilities.h:15]
#5 CreatePolygon [main.cpp:77]
#6 main [main.cpp:58]
Note: @0:00:02.574 in thread 743983
Note: instruction: movsd 0x38(%edx) -> %xmm0

Error `#240`: UNINITIALIZED READ: reading 0xbff82ba0-0xbff82ba8 8 byte(s)
#0 libunwind.dylib!unw_init_local
#1 libunwind.dylib!unwind_phase2
#2 libunwind.dylib!_Unwind_Resume
#3 IsoscelesTriangle::IsoscelesTriangle [./utilities.h:15]
#4 CreatePolygon [main.cpp:89]
#5 main [main.cpp:58]
Note: @0:00:03.209 in thread 743983
Note: instruction: movsd 0x20(%edx) -> %xmm0

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=1452_