Fixes a bug in ASM where invalid input LVT entries can translate into negative length output LVT entries, which causes a ClassFormatError when the JVM tries to load it.

See: http://forge.objectweb.org/tracker/?func=detail&atid=100023&aid=310932&group_id=23

The change simply omits any LVT entries with unresolved (and thus, invalid) start or end labels.

Review by: tobyr (TBR)

Files:
modified: /trunk/dev/core/src/com/google/gwt/dev/asm/MethodWriter.java (try)