[urgent] RFR: JDK-8145206: Configure broken on Macosx

[Erik Joelsson]

JDK-8036003 broke configure on Macosx:

checking what type of native debug symbols to use... zipped
configure: error: Unable to find objcopy, cannot enable native debug 
symbols

We can only fail for missing objcopy on platforms that actually use it.

Bug: https://bugs.openjdk.java.net/browse/JDK-8145206
Webrev: http://cr.openjdk.java.net/~erikj/8145206/webrev.01/

/Erik