ReleaseNotes: add lld/ELF notes

Differential Revision: https://reviews.llvm.org/D97113

Author: MaskRay

lld/docs/ReleaseNotes.rst

@@ -24,13 +24,77 @@ Non-comprehensive list of changes in this release
 ELF Improvements
 ----------------
 
-* ``--error-handling-script`` is added to allow for user-defined handlers upon
+* ``--dependency-file`` has been added. (Similar to ``cc -M -MF``.)
+  (`D82437 <https://reviews.llvm.org/D82437>`_)
+* ``--error-handling-script`` has been added to allow for user-defined handlers upon
   missing libraries. (`D87758 <https://reviews.llvm.org/D87758>`_)
+* ``--exclude-libs`` can now localize defined version symbols and bitcode referenced libcall symbols.
+  (`D94280 <https://reviews.llvm.org/D94280>`_)
+* ``--gdb-index`` now works with DWARF v5 and ``--icf={safe,all}``.
+  (`D85579 <https://reviews.llvm.org/D85579>`_)
+  (`D89751 <https://reviews.llvm.org/D89751>`_)
+* ``--gdb-index --emit-relocs`` can now be used together.
+  (`D94354 <https://reviews.llvm.org/D94354>`_)
+* ``--icf={safe,all}`` conservatively no longer fold text sections with LSDA.
+  Previously ICF on ``-fexceptions`` code could be unsafe.
+  (`D84610 <https://reviews.llvm.org/D84610>`_)
+* ``--icf={safe,all}`` can now fold two sections with relocations referencing aliased symbols.
+  (`D88830 <https://reviews.llvm.org/D88830>`_)
+* ``--lto-pseudo-probe-for-profiling`` has been added.
+  (`D95056 <https://reviews.llvm.org/D95056>`_)
+* ``--no-lto-whole-program-visibility`` has been added.
+  (`D92060 <https://reviews.llvm.org/D92060>`_)
+* ``--oformat-binary`` has been fixed to respect LMA.
+  (`D85086 <https://reviews.llvm.org/D85086>`_)
+* ``--reproduce`` includes ``--lto-sample-profile``, ``--just-symbols``, ``--call-graph-ordering-file``, ``--retain-symbols-file`` files.
+* ``-r --gc-sections`` is now supported.
+  (`D84131 <https://reviews.llvm.org/D84131>`_)
+* A ``-u`` specified symbol will no longer change the binding to ``STB_WEAK``.
+  (`D88945 <https://reviews.llvm.org/D88945>`_)
+* ``--wrap`` support has been improved.
+  + If ``foo`` is not referenced, there is no longer an undefined symbol ``__wrap_foo``.
+  + If ``__real_foo`` is not referenced, there is no longer an undefined symbol ``foo``.
+* ``SHF_LINK_ORDER`` sections can now have zero ``sh_link`` values.
+* ``SHF_LINK_ORDER`` and non-``SHF_LINK_ORDER`` sections can now be mixed within an input section description.
+  (`D84001 <https://reviews.llvm.org/D84001>`_)
+* ``LOG2CEIL`` is now supported in linker scripts.
+  (`D84054 <https://reviews.llvm.org/D84054>`_)
+* ``DEFINED`` has been fixed to check whether the symbol is defined.
+  (`D83758 <https://reviews.llvm.org/D83758>`_)
+* An input section description may now have multiple ``SORT_*``.
+  The matched sections are ordered by radix sort with the keys being ``(SORT*, --sort-section, input order)``.
+  (`D91127 <https://reviews.llvm.org/D91127>`_)
+* Users can now provide a GNU style linker script to convert ``.ctors`` into ``.init_array``.
+  (`D91187 <https://reviews.llvm.org/D91187>`_)
+* An empty output section can now be discarded even if it is assigned to a program header.
+  (`D92301 <https://reviews.llvm.org/D92301>`_)
+* Non-``SHF_ALLOC`` sections now have larger file offsets than ``SHF_ALLOC`` sections.
+  (`D85867 <https://reviews.llvm.org/D85867>`_)
+* Some symbol versioning improvements.
+  + Defined ``foo@@v1`` now resolve undefined ``foo@v1`` (`D92259 <https://reviews.llvm.org/D92259>`_)
+  + Undefined ``foo@v1`` now gets an error (`D92260 <https://reviews.llvm.org/D92260>`_)
+* The AArch64 port now has support for ``STO_AARCH64_VARIANT_PCS`` and ``DT_AARCH64_VARIANT_PCS``.
+  (`D93045 <https://reviews.llvm.org/D93045>`_)
+* The AArch64 port now has support for ``R_AARCH64_LD64_GOTPAGE_LO15``.
+* The PowerPC64 port now detects missing R_PPC64_TLSGD/R_PPC64_TLSLD and disables TLS relaxation.
+  This allows linking with object files produced by very old IBM XL compilers.
+  (`D92959 <https://reviews.llvm.org/D92959>`_)
+* Many PowerPC PC-relative relocations are now supported.
+* ``R_PPC_ADDR24`` and ``R_PPC64_ADDR16_HIGH`` are now supported.
+* powerpcle is now supported. Tested with FreeBSD loader and freestanding.
+  (`D93917 <https://reviews.llvm.org/D93917>`_)
+* RISC-V: the first ``SHT_RISCV_ATTRIBUTES`` section is now retained.
+  (`D86309 <https://reviews.llvm.org/D86309>`_)
+* LTO pipeline now defaults to the new PM if the CMake variable ``ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER`` is on.
+  (`D92885 <https://reviews.llvm.org/D92885>`_)
 
 Breaking changes
 ----------------
 
-* ...
+* A COMMON symbol can now cause the fetch of an archive providing a ``STB_GLOBAL`` definition.
+  This behavior follows GNU ld newer than December 1999.
+  If you see ``duplicate symbol`` errors with the new behavior, check out `PR49226 <https://bugs.llvm.org//show_bug.cgi?id=49226>`_.
+  (`D86142 <https://reviews.llvm.org/D86142>`_)
 
 COFF Improvements
 -----------------