Restore correct postfix parsing (#94)

Author: ahejlsberg

internal/compiler/parser.go

@@ -2233,11 +2233,18 @@ func (p *Parser) parsePostfixTypeOrHigher() *ast.Node {
 	typeNode := p.parseNonArrayType()
 	for !p.hasPrecedingLineBreak() {
 		switch p.token {
+		case ast.KindExclamationToken:
+			p.nextToken()
+			typeNode = p.factory.NewJSDocNonNullableType(typeNode)
+			p.finishNode(typeNode, pos)
 		case ast.KindQuestionToken:
 			// If next token is start of a type we have a conditional type
 			if p.lookAhead(p.nextIsStartOfType) {
 				return typeNode
 			}
+			p.nextToken()
+			typeNode = p.factory.NewJSDocNullableType(typeNode)
+			p.finishNode(typeNode, pos)
 		case ast.KindOpenBracketToken:
 			p.parseExpected(ast.KindOpenBracketToken)
 			if p.isStartOfType(false /*isStartOfParameter*/) {