Revert r129235 pending a vetting of the EH rewrite.

--- Reverse-merging r129235 into '.':
D    test/Feature/bb_attrs.ll
U    include/llvm/BasicBlock.h
U    include/llvm/Bitcode/LLVMBitCodes.h
U    lib/VMCore/AsmWriter.cpp
U    lib/VMCore/BasicBlock.cpp
U    lib/AsmParser/LLParser.cpp
U    lib/AsmParser/LLLexer.cpp
U    lib/AsmParser/LLToken.h
U    lib/Bitcode/Reader/BitcodeReader.cpp
U    lib/Bitcode/Writer/BitcodeWriter.cpp

llvm-svn: 129259