Merge branch 'kbuild' of git://

Pull kbuild updates from Michal Marek:
 - make clean also considers $(extra-m) and $(extra-) to be consistent
 - cleanup and fixes in scripts/
 - allow to override the name of the Python 2 executable with make
   PYTHON=... (only needed for ia64 in practice)
 - option to split debugingo into *.dwo files to save disk space if the
   compiler supports it (CONFIG_DEBUG_INFO_SPLIT)
 - option to use dwarf4 debuginfo if the compiler supports it
 - fix for disabling certain warnings with clang
 - fix for unneeded rebuild with dash when a command contains

* 'kbuild' of git://
  kbuild: Fix handling of backslashes in *.cmd files
  kbuild, LLVMLinux: Supress warnings unless W=1-3
  Kbuild: Add a option to enable dwarf4 v2
  kbuild: Support split debug info v4
  kbuild: allow to override Python command name
  kbuild: clean-up and bug fix of scripts/
  kbuild: clean up scripts/
  kbuild: drop shared library support from
  kbuild: fix a bug of C++ host program handling
  kbuild: fix a typo in scripts/
  scripts/Makefile.clean: clean also $(extra-m) and $(extra-)