[Modules] Make Support/Debug.h modular. This requires it to not change
behavior based on other files defining DEBUG_TYPE, which means it cannot
define DEBUG_TYPE at all. This is actually better IMO as it forces folks
to define relevant DEBUG_TYPEs for their files. However, it requires all
files that currently use DEBUG(...) to define a DEBUG_TYPE if they don't
already. I've updated all such files in LLVM and will do the same for
other upstream projects.

This still leaves one important change in how LLVM uses the DEBUG_TYPE
macro going forward: we need to only define the macro *after* header
files have been #include-ed. Previously, this wasn't possible because
Debug.h required the macro to be pre-defined. This commit removes that.
By defining DEBUG_TYPE after the includes two things are fixed:

- Header files that need to provide a DEBUG_TYPE for some inline code
  can do so by defining the macro before their inline code and undef-ing
  it afterward so the macro does not escape.

- We no longer have rampant ODR violations due to including headers with
  different DEBUG_TYPE definitions. This may be mostly an academic
  violation today, but with modules these types of violations are easy
  to check for and potentially very relevant.

Where necessary to suppor headers with DEBUG_TYPE, I have moved the
definitions below the includes in this commit. I plan to move the rest
of the DEBUG_TYPE macros in LLVM in subsequent commits; this one is big
enough.

The comments in Debug.h, which were hilariously out of date already,
have been updated to reflect the recommended practice going forward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206822 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify DFAPacketizerEmitter State copy/move semantics to use compiler defaults.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206824 91177308-0d34-0410-b5e6-96231b3b80d8
Fix wrong iterator type

ELFEntityIterator does not implement RandomAccessIterator. It does
not even implement BidirectionalIterator.

This patch fixes LLD build issue when compiled with MSVC2013 with
debug: MSVC's find_if checks if the start iterator is before the end
iterator in the sense of operator< if it declares implementing
RandomAccessIterator. If a class does not have operator<, it fails
to compile.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206825 91177308-0d34-0410-b5e6-96231b3b80d8
Use unique_ptr to handle ownership of Value*s in Cloning unit tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206828 91177308-0d34-0410-b5e6-96231b3b80d8