This patch adds an option to limit debug info by only emitting complete class
type information when its constructor is emitted. This applies to classes
that have nontrivial user defined constructors.
I implemented the option by adding another level to DebugInfoKind, and
a flag -flimit-debug-info-constructor.
Total object file size on Windows, compiling with RelWithDebInfo:
before: 4,257,448 kb after: 2,104,963 kb
And on Linux
before: 9,225,140 kb after: 4,387,464 kb
According to the Windows clang.pdb files, here is a list of types that are no
longer complete with this option enabled: https://reviews.llvm.org/P8182