Previously, the static resolver did its own interpretation of statements
in the TypeScript AST, which only functioned on TypeScript code. ES5
code in particular would not work with the resolver as it had hard-coded
assumptions about AST structure.
This commit changes the resolver to use a ReflectionHost instead, which
abstracts away understanding of the structural side of the AST. It adds 3
new methods to the ReflectionHost in support of this functionality:
* getDeclarationOfIdentifier
* getExportsOfModule
* isClass
PR Close#24862