Properly resolve function type from function name (AssemblyScript#833)

Author: dcodeIO

src/compiler.ts

@@ -8103,6 +8103,7 @@ export class Compiler extends DiagnosticEmitter {
     );
 
     // Try to eliminate unnecesssary branches if the condition is constant
+    // FIXME: skips common denominator, inconsistently picking left type
     if (
       getExpressionId(condExpr) == ExpressionId.Const &&
       getExpressionType(condExpr) == NativeType.I32

src/resolver.ts

@@ -1025,6 +1025,11 @@ export class Resolver extends DiagnosticEmitter {
   ): Type | null {
     var element = this.lookupIdentifierExpression(node, ctxFlow, ctxElement, reportMode);
     if (!element) return null;
+    if (element.kind == ElementKind.FUNCTION_PROTOTYPE) {
+      let instance = this.resolveFunction(<FunctionPrototype>element, null, makeMap(), reportMode);
+      if (!instance) return null;
+      element = instance;
+    }
     var type = this.getTypeOfElement(element);
     if (!type) {
       if (reportMode == ReportMode.REPORT) {