Minor ReleaseNotes fixes

Undefined Behavior Sanitizer (UBSan)

------------------------------------

- * The ``pointer-overflow`` check was extended added to catch the cases where

* The ``pointer-overflow`` check was extended added to catch the cases where

  a non-zero offset is applied to a null pointer, or the result of

  applying the offset is a null pointer.

* Allow using custom .edata sections from input object files (for use

  by Wine)

  (`dadc6f248868 <https://reviews.llvm.org/rGdadc6f248868>`)

  (`dadc6f248868 <https://reviews.llvm.org/rGdadc6f248868>`_)

* Don't implicitly create import libraries unless requested

  (`6540e55067e3 <https://reviews.llvm.org/rG6540e55067e3>`)

  (`6540e55067e3 <https://reviews.llvm.org/rG6540e55067e3>`_)

* Support merging multiple resource object files

  (`3d3a9b3b413d <https://reviews.llvm.org/rG3d3a9b3b413d>`)

  (`3d3a9b3b413d <https://reviews.llvm.org/rG3d3a9b3b413d>`_)

  and properly handle the default manifest object files that GCC can pass

  (`d581dd501381 <https://reviews.llvm.org/rGd581dd501381>`)

  (`d581dd501381 <https://reviews.llvm.org/rGd581dd501381>`_)

* Demangle itanium symbol names in warnings/error messages

  (`a66fc1c99f3e <https://reviews.llvm.org/rGa66fc1c99f3e>`)

  (`a66fc1c99f3e <https://reviews.llvm.org/rGa66fc1c99f3e>`_)

* Print source locations for undefined references and duplicate symbols,

  if possible

  (`1d06d48bb346 <https://reviews.llvm.org/rG1d06d48bb346>`)

  (`1d06d48bb346 <https://reviews.llvm.org/rG1d06d48bb346>`_)

  and

  (`b38f577c015c <https://reviews.llvm.org/rGb38f577c015c>`)

  (`b38f577c015c <https://reviews.llvm.org/rGb38f577c015c>`_)

* Look for more filename patterns when resolving ``-l`` options

  (`0226c35262df <https://reviews.llvm.org/rG0226c35262df>`)

  (`0226c35262df <https://reviews.llvm.org/rG0226c35262df>`_)

* Don't error out on duplicate absolute symbols with the same value

  (which can happen for the default-null symbol for weak symbols)

  (`1737cc750c46 <https://reviews.llvm.org/rG1737cc750c46>`)

  (`1737cc750c46 <https://reviews.llvm.org/rG1737cc750c46>`_)

WebAssembly Improvements

  with optimizations enabled.

* ``Callbacks`` have been added to ``CommandLine Options``.  These can

  be used to validate of selectively enable other options.

  be used to validate or selectively enable other options.

* The function attributes ``no-frame-pointer-elim`` and

  ``no-frame-pointer-elim-non-leaf`` have been replaced by ``frame-pointer``,

  `D59918 <https://reviews.llvm.org/D59918>`_, `LLVM-Dev talk <https://youtu.be/CzWkc_JcfS0>`_).

  In this release, 19 different attributes are inferred, including 12 LLVM IR

  attributes and 7 "abstract" attributes, such as liveness. The Attributor is

  still under heavy development and disabled by default, to enable an early run

  still under heavy development and disabled by default; to enable an early run

  pass ``-mllvm -attributor-disable=false`` to an invocation of clang.

* New matrix math intrinsics have been added to LLVM

* Enabled vectorization of math routines on PowerPC using MASSV (Mathematical Acceleration SubSystem) library

compiler-rt:

copiler-rt:

* Added/improved conversion functions from IBM long double to 128-bit integers

Changes to the X86 Target

-------------------------

 During this release ...

* Less than 128 bit vector types, v2i32, v4i16, v2i16, v8i8, v4i8, and v2i8, are

* Less-than-128-bit vector types, v2i32, v4i16, v2i16, v8i8, v4i8, and v2i8, are

  now stored in the lower bits of an xmm register and the upper bits are

  undefined. Previously the elements were spread apart with undefined bits in

  between them.

  than the ABI register names.

Improvements:

* Trap and Debugtrap now lower to RISC-V-specific trap instructions.

* LLVM IR Inline assembly now supports using ABI register names and using