[flang] Miscellaneous name resolution

Handle BIND statement and PARAMETER statement. They are different from
other attribute-setting statements so some refactoring of
HandleAttributeStmt is required. And for PARAMETER, SetType needs to
report an error if the implicitly determined type is changed later. This
requires operator== on DeclTypeSpec.

Resolve names in allocate statements, pointer assignment statements,
substring expressions, and type parameter values.

Original-commit: flang-compiler/f18@79ad96b976c495dcc836267bd08276c4a6be8bb4
Reviewed-on: https://github.com/flang-compiler/f18/pull/177