RFR: JDK-8236469: macOS devkit needs 64-bit SetFile for Catalina

[Erik Joelsson]

Hello,

When building JDK 15 with the current devkit on a Catalina host, the 
build fails. This is because the SetFile command is picked up from the 
devkit and in the Xcode version the devkit is based on, that executable 
is 32bit. I had expected to update the compiler version used at Oracle 
in JDK 15, but as we are running out of time, that won't happen until 
JDK 16. So to make JDK 15 more easily buildable on Catalina for Oracle 
engineers, I'm applying a simple workaround in the jib profile for 
macosx-x64. The workaround is to force the use of /usr/bin/SetFile.

Bug: https://bugs.openjdk.java.net/browse/JDK-8236469

Webrev: http://cr.openjdk.java.net/~erikj/8236469/webrev.01/

/Erik