JDK mainline build fails on macosx with XCode 16

[Jaikiran Pai]

In the past few days there have been reports of the JDK mainline build 
failing on macosx when using (the recently released) XCode 16 as the 
toolchain. Doing a regular JDK build runs into:

Exception in thread "main" java.lang.ClassFormatError: StackMapTable 
format error: bad verification type
         at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:64)
         at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:52)

This has been investigated into and the issue appears to be a bug in the 
clang++ compiler (shipped in XCode 16). The issue along with the 
complete details of this issue are being tracked in 
https://bugs.openjdk.org/browse/JDK-8340341. Additionally, this has been 
reported to Apple through their feedback assistance tool (issue id 
FB15162411).

At this point, there is a workaround (also noted in the JDK-8340341 
issue and the workaround patch attached to that issue), but my personal 
recommendation would be to stay with older versions of Xcode that work, 
because even with the workaround it's unknown whether this compiler 
issue has wider implications in other places of the JDK.

The reports so far have been on macosx aarch64, but it might be because 
no one so far has tried this on macosx x64 (with XCode 16).

-Jaikiran