JDK 9 RFR of JDK-8162539: Test fails because it expects a blank between method signature and throws exception

[joe darcy]

Hello,

Please review the changes to address

     JDK-8162539: Test fails because it expects a blank between method 
signature and throws exception
     http://cr.openjdk.java.net/~darcy/8162539.0/

In brief, recent refactorings of the toString output in core reflection 
(JDK-8161500 Use getTypeName and StringJoiner in core reflection generic 
toString methods) omitted a space character between the closing ")" and 
"throws" for toString output, but correctly included the space in 
toGenericString output.

The simple fix is to add the space character; regression tests are 
suitably augmented and slightly refactored.

Thanks,

-Joe