No way to do builder.createStore() for float or half constants

[Diego Perini]

In order to be able to work with non double floating point constants, we need the mappings for APFloat and ConstantFP::get(Type* Ty, const APFloat &V) APIs.

http://llvm.org/doxygen/classllvm_1_1APFloat.html
http://llvm.org/doxygen/classllvm_1_1ConstantFP.html#ac698873f7b353f3a37cb8577b74acf72

[Diego Perini]

I will look into it once the contribution guidelines are up.

[Dmitry Patsura]

@MichaReiser Can you assign this issue to me? I will start to work on it on weekends, Thanks!