Bug 20792 – Emit standard DWARF3 opcode for TLS address

Mathias Lang reports: DW_OP_GNU_push_tls_address is a GNU extension prior to DWARF2. DWARF3 introduced DW_OP_form_tls_address with the exact same semantic, as can be seen here: https://sourceware.org/legacy-ml/gdb-patches/2016-08/msg00222.html https://reviews.llvm.org/rL274366 Caveat: GDB support was "only" added in 7.12, which was released on 2016-10-07. Since I don't use DMD (debug infos are utterly broken on MacOSX), I didn't observe any downside of this, but I was going over the DWARF code and found this oddity and figured it was time to replace it. https://github.com/dlang/dmd/pull/11087

THIS ISSUE HAS BEEN MOVED TO GITHUB https://github.com/dlang/dmd/issues/17953 DO NOT COMMENT HERE ANYMORE, NOBODY WILL SEE IT, THIS ISSUE HAS BEEN MOVED TO GITHUB