Apply multiple specialisation to cases of (partially) known values of arguments

[pschachte]

This can significantly help higher order procedures where the HO argument is statically known, by generating a first order procedure. For example, a call map(+(1), ...) would cause the compiler to generate a specialised procedure that increments each element of a list, and would call this instead. The generated code would then approach what a C programmer would write to add 1 to each element of a list.