Simplify some long/complex methods in Compiler code

[hopscc]

Prototype complexity metrics code run on compiler shows some methods
with linecount>100 and rough mccabe complexity >25.

These should probably be shortened and simplified.

METHOD                                 LINES   McCABE
Compiler.__loadReference               53      27 
          IfStmt._bindImp              84      29
CobraParser.typeSpecDecls              78      30
CobraParser.declareMethod              128     33

[hopscc]

Heres a more complete List

                                      ...METHOD...              LINES   McCABE
                          Compiler.__loadReference              81      27
                             Compiler.compileSharp              102     21
                         CobraParser.declareMethod              132     34
                           CobraParser.expression2              122     41
                                  CobraParser.stmt              109     11
                         CobraParser.typeSpecDecls              78      26
                ClrTypeProxy._realTypeWithoutCache              119     28
                MemberOverload.computeBestOverload              90      31
                                   IfStmt._bindImp              86      26
                         NumericPromoExpr._bindImp              88      31

[hopscc]

Refactoring of all methods >100 LOC or CCC >25. shorten and/or simplify.
No new tests.

[Chuck]

Applied in changeset:2451