Instrument: Correctly set isVar for nested function declarations [i…

…mprove]

Makes no actual difference, as `isVar` is only used minimally, but better to make it correct.

lib/instrument/visitors/function.js

@@ -86,11 +86,12 @@ function FunctionDeclaration(node, state, parent, key) {
 		// Existing binding must be a `var` declaration or another function declaration
 		binding.isFunction = true;
 	} else {
-		binding = createBinding(block, fnName, {isVar: true, isFunction: true}, state);
+		const isTopLevel = block === hoistBlock;
+		binding = createBinding(block, fnName, {isVar: isTopLevel, isFunction: true}, state);
 
 		// If is a sloppy-mode function declaration which may need to be hoisted, record that.
 		// Determine whether to hoist after 1st pass is complete, once all other bindings created.
-		if (block !== hoistBlock && !state.isStrict && !node.async && !node.generator) {
+		if (!isTopLevel && !state.isStrict && !node.async && !node.generator) {
 			state.sloppyFunctionDeclarations.push({varName: fnName, binding, block, hoistBlock});
 		}
 	}
@@ -564,7 +565,7 @@ function hoistSloppyFunctionDeclaration(declaration) {
 	if (hoistBlockBinding) {
 		hoistBlockBinding.isFunction = true;
 	} else {
-		hoistBlock.bindings[varName] = declaration.binding;
+		hoistBlock.bindings[varName] = {...declaration.binding, isVar: true};
 	}
 }