Bug 2124345

.Valgrind rebased to version 3.21.0 Valgrind has been updated to version 3.21.0. Notable enhancements include: * A new `abexit` value for the `--vgdb-stop-at=_event1_,_event2_,...` option notifies the `gdbserver` utility when your program exits abnormally, such as with a non-zero exit code. * A new `--enable-debuginfod=[yes|no]` option instructs Valgrind to use the `debuginfod` servers listed in the `DEBUGINFOD_URLS` environment variable to fetch any missing DWARF debuginfo information for the program running under Valgrind. The default value for this option is `yes`. + NOTE: The `DEBUGINFOD_URLS` environment variable is not set by default. * The `vgdb` utility now supports the extended remote protocol when invoked with the `--multi` option. The GDB `run` command is supported in this mode and, as a result, you can run GDB and Valgrind from a single terminal. * You can use the `--realloc-zero-bytes-frees=[yes|no]` option to change the behavior of the `realloc()` function with a size of zero for tools that intercept the `malloc()` call. * The `memcheck` tool now performs checks for the use of the `realloc()` function with a size of zero. Use the new `--show-realloc-size-zero=[yes|no]` switch to disable this feature. * You can use the new `--history-backtrace-size=_value_` option for the `helgrind` tool to configure the number of entries to record in the stack traces of earlier accesses. * The `--cache-sim=[yes|no]` `cachegrind` option now defaults to `no` and, as a result, only instruction cache read events are gathered by default. * The source code for the `cg_annotate`, `cg_diff`, and `cg_merge` `cachegrind` utilities has been rewritten and, as a result, the utilities have more flexible command line option handling. For example, they now support the `--show-percs` and `--no-show-percs` options as well as the existing `--show-percs=yes` and `--show-percs=no` options. * The `cg_annotate` `cachegrind` utility now supports diffing (using the `--diff`, `--mod-filename`, and `--mod-funcname` options) and merging (by passing multiple data files). In addition, `cg_annotate` now provides more information at the file and function level. * A new user-request for the `DHAT` tool allows you to override the 1024 byte limit on access count histograms for blocks of memory. The following new architecture-specific instruction sets are now supported: * 64-bit ARM: ** v8.2 scalar and vector Floating-point Absolute Difference (FABD), Floating-point Absolute Compare Greater than or Equal (FACGE), Floating-point Absolute Compare Greater Than (FACGT), and Floating-point Add (FADD) instructions. ** v8.2 Floating-point (FP) compare and conditional compare instructions. ** Zero variants of v8.2 Floating-point (FP) compare instructions. * 64-bit IBM Z: ** Support for the `miscellaneous-instruction-extensions facility 3` and the `vector-enhancements facility 2`. This enables programs compiled with the `-march=arch13` or `-march=z15` options to be executed under Valgrind. * IBM Power: ** ISA 3.1 support is now complete. ** ISA 3.0 now supports the deliver a random number (darn) instruction. ** ISA 3.0 now supports the System Call Vectored (scv) instruction. ** ISA 3.0 now supports the copy, paste, and cpabort instructions.