Use std::unique_ptr to manage MCBasicBlocks in MCFunction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206242 91177308-0d34-0410-b5e6-96231b3b80d8
[C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206243 91177308-0d34-0410-b5e6-96231b3b80d8
Use unique_ptr to own MCFunctions within MCModule.

MCModule's ctor had to be moved out of line so the definition of
MCFunction was available. (ctor requires the dtor of members (in case
the ctor throws) which required access to the dtor of MCFunction)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206244 91177308-0d34-0410-b5e6-96231b3b80d8
Use unique_ptr for section/segment ownership in WinCOFFObjectWriter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206245 91177308-0d34-0410-b5e6-96231b3b80d8
Use unique_ptr to manage ownership of GCStrategy objects in GCMetadata

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206246 91177308-0d34-0410-b5e6-96231b3b80d8
Use unique_ptr for the result of Registry entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206248 91177308-0d34-0410-b5e6-96231b3b80d8