new AST type inference pass

[ppaulweber]

• • accordingly to the new AST from new AST in-memory represenation #19 implement a new generic type checker, resolver and inference pass
• • the pass name shall be src/analyze/TypeInferencePass{.h,.cpp}
  • implementation ideas:
    • http://www.selflanguage.org/_static/published/cpa.pdf
    • http://stevehanov.ca/cs744_type_inference_project.pdf

[ppaulweber]

new branch name https://github.com/casm-lang/libcasm-fe/tree/feature/20_new_type_inference

[ppaulweber]

@emmanuel099: latest commit casm-lang/libcasm-fe@3b1c3d3 is able to fully type inference the following example specification:

CASM init foo

enum Color = { Red, Green, Blue }
enum Angle = { Alpha, Beta, Gamma }

rule foo =
{
    let c : Color = .Red in // Color namespace from type of c
        skip

    let c = Color.Green in
        case c of // cases should use Color namespace of c
        {
            .Red: assert(false)
            .Green:
		case Angle.Beta of
		{
		    .Alpha: bar( 4 ) := bar( 10 + bar( 2 ) )
		    .Beta:  skip
		    .Gamma: skip		    
		}
            .Blue: assert(false)
        }

    bar( 1 ) := bar( bar( bar( 9 ) + 1 ) - 10 ) * 100

    program(self) := undef
}

[ static ]
function qux : -> Integer'[1..5] initially { 3 }

function bar : Integer -> Integer initially { qux -> qux } 

function mem : Bit'4 -> Bit'64

derived blub( a, b ) -> Integer = ( a + b )

rule lala( f ) =
{
    print( f )
    call foo
}

still there is a problem with the 'Agent' type of the 'program' function, but I'll fix this ASAP in the next commit

[ppaulweber]

merged into #32