make check RUNTESTFLAGS=jmain.exp
gdb testsuite/gdb.java/jmain
(gdb) b jmain.jmain
(gdb) b jmain::main

The "b jmain::jmain" works because the corresponding minsym got demangled as c++.

This also means that LOC_UNRESOLVED is (I think, still have to verify it) broken for Java.  LOC_UNRESOLVED does minsym lookup based on the demangled name derived from DWARF, but in DWARF we know we have Java.  So I'm guessing a LOC_UNRESOLVED minsym lookup for "foo.bar" will fail because the minsym got demangled as "foo::bar".

Note: The code to process LOC_UNRESOLVED is in findvar.c:

        memset (&lookup_data, 0, sizeof (lookup_data));
        lookup_data.name = SYMBOL_LINKAGE_NAME (var);

Heads up when you read this: SYMBOL_LINKAGE_NAME here is actually the demangled name.

I have a significant rework of minsym support in progress.
Hopefully I can address this with this patch.

To fix LOC_UNRESOLVED I think what we really need to do is do the minsym lookup using the mangled name. That's the topic of another patch in progress.