[Debugger] Implement DW_OP_gnu_entry_value support
|Reported by:||anevilyak||Owned by:||anevilyak|
For optimized release binaries with debug information, gcc4.x has started emitting expression opcode DW_OP_gnu_entry_value (0xf3). This one needs to be handled at some point in order to resolve values in such a circumstance. From the vague documentation located so far, it'd appear to also require more complete handling of DW_TAG_gnu_call_site, which we currently parse but otherwise ignore.