llvm: split packages a bit more

* use split for llvm3.* like we did for llvm2.*
* use PACKAGESPLITFUNCS instead of populate_packages_prepend
* improve regexp in PACKAGES_DYNAMIC
* append ${LLVM_RELEASE} to split package name, otherwise sstate
  will complain about multiple recipes trying to install pkgdata
* split also -staticdev and -dbg libs, PN-dbg and PN-staticdev
  were huge, let old PN-dbg/PN-staticdev to RDEPEND on splitted
  packages
* mesa packages libegl-gallium, libgbm-gallium, mesa-driver-pipe-swrast,
  mesa-driver-pipe-vmwgfx, mesa-driver-swrast, mesa-driver-vmwgfx are
  now depending only on libllvm3.2-llvm-3.2 (>= 3.2) instead of main
  llvm3.2 package, but for llvm-3* it's not big improvement
  (installed size wise), because libLLVM-3.2.so was creating 99% of that
  size.
* there are still some huge packages:
  llvm2.8-dbg is huge because BUILD_SHARED_LIBS is disabled for 2.8
              causing all binaries in ${bindir}/.debug to contain big
              static libs
  llvm2.9 is missing, because it has BUILD_SHARED_LIBS enabled and
          unlike 3.* it doesn't build static versions at all unless
          explicitly requested

  51M     llvm-test/llvm3.2/3.2-r0/packages-split/libllvm3.2-llvmselectiondag-staticdev
  53M     llvm-test/llvm2.8/2.8-r3/packages-split/llvm2.8-dev
  54M     llvm-test/llvm2.8/2.8-r3/packages-split/libllvm2.8-llvmanalysis-staticdev
  55M     llvm-test/llvm3.3/3.3-r0/packages-split/libllvm3.3-llvmselectiondag-staticdev
  62M     llvm-test/llvm3.2/3.2-r0/packages-split/libllvm3.2-llvmanalysis-staticdev
  63M     llvm-test/llvm3.3/3.3-r0/packages-split/libllvm3.3-llvmanalysis-staticdev
  67M     llvm-test/llvm2.9/2.9-r3/packages-split/llvm2.9-dbg
  90M     llvm-test/llvm3.2/3.2-r0/packages-split/llvm3.2-dbg
  92M     llvm-test/llvm3.3/3.3-r0/packages-split/llvm3.3-dbg
  102M    llvm-test/llvm2.8/2.8-r3/packages-split/libllvm2.8-llvmcodegen-staticdev
  127M    llvm-test/llvm3.2/3.2-r0/packages-split/libllvm3.2-llvmcodegen-staticdev
  133M    llvm-test/llvm3.3/3.3-r0/packages-split/libllvm3.3-llvmcodegen-staticdev
  190M    llvm-test/llvm3.2/3.2-r0/packages-split/libllvm3.2-llvm-3.2-dbg
  207M    llvm-test/llvm3.3/3.3-r0/packages-split/libllvm3.3-llvm-3.3-dbg
  628M    llvm-test/llvm2.8/2.8-r3/packages-split/llvm2.8-dbg

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>