[DWARF] Add GNU extensions for call site info DWARF symbols

[djtodoro]

Summary

As discussed on RFC (http://lists.llvm.org/pipermail/llvm-dev/2019-February/130094.html), this is set of patches that introduces debug information about call site and call site parameters. Since LLVM has portion of this support (dumping DWARF 5 symbols for calls), we generate GNU extensions as well. All of that will be restricted under an option, until we do all necessary testing and patching.

The latest set of patches introduces proposal for implementing the functionality as late MIR analysis.

Authors: @asowda, @NikolaPrica, @djtodoro, @ivanbaev

[vsk]

Is there a separate patch which adds DWARF verifier support for these new attributes? If not, this could be the right vehicle for it.

[djtodoro]

@vsk Thanks for your comment! We will add DWARF verifier support for the GNU extensions.

llvm/trunk/include/llvm/BinaryFormat/Dwarf.def

 HANDLE_DW_AT(0x2103, mac_info, 0, GNU)
 HANDLE_DW_AT(0x2104, src_coords, 0, GNU)
 HANDLE_DW_AT(0x2105, body_begin, 0, GNU)
 HANDLE_DW_AT(0x2106, body_end, 0, GNU)
 HANDLE_DW_AT(0x2107, GNU_vector, 0, GNU)
 HANDLE_DW_AT(0x2110, GNU_template_name, 0, GNU)
 HANDLE_DW_AT(0x210f, GNU_odr_signature, 0, GNU)
 HANDLE_DW_AT(0x2111, GNU_call_site_value, 0, GNU)
+HANDLE_DW_AT (0x2112, GNU_call_site_data_value, 0, GNU)
+HANDLE_DW_AT (0x2113, GNU_call_site_target, 0, GNU)
+HANDLE_DW_AT (0x2114, GNU_call_site_target_clobbered, 0, GNU)
+HANDLE_DW_AT (0x2115, GNU_tail_call, 0, GNU)
+HANDLE_DW_AT (0x2116, GNU_all_tail_call_sites, 0, GNU)
 HANDLE_DW_AT(0x2117, GNU_all_call_sites, 0, GNU)
+HANDLE_DW_AT (0x2118, GNU_all_source_call_sites, 0, GNU)
 HANDLE_DW_AT(0x2119, GNU_macros, 0, GNU)
 // Extensions for Fission proposal.
 HANDLE_DW_AT(0x2130, GNU_dwo_name, 0, GNU)
 HANDLE_DW_AT(0x2131, GNU_dwo_id, 0, GNU)
 HANDLE_DW_AT(0x2132, GNU_ranges_base, 0, GNU)
 HANDLE_DW_AT(0x2133, GNU_addr_base, 0, GNU)
 HANDLE_DW_AT(0x2134, GNU_pubnames, 0, GNU)
 HANDLE_DW_AT(0x2135, GNU_pubtypes, 0, GNU)