Update README

Signed-off-by: Pekka Enberg <penberg@iki.fi>
Fix LLVM include paths

Signed-off-by: Pekka Enberg <penberg@iki.fi>
CMake: Use -Wno-unused-parameter

Signed-off-by: Pekka Enberg <penberg@iki.fi>
Make getFloatType non-const

llvm::ConstantFP.get() expects non-cost type...

Signed-off-by: Pekka Enberg <penberg@iki.fi>
Fix const issues with LLVM API

Signed-off-by: Pekka Enberg <penberg@iki.fi>