Merge bitcoin/bitcoin#23383: Update libsecp256k1 subtree to current master

314195c8be3bd7db0d5817c4fb3aa85c84363ce9 Remove unnecessary cast in CKey::SignSchnorr (Pieter Wuille)
a1f76cdb22e3278a48d63dd23c1fe3308daedd8c Remove --disable-openssl-tests for libsecp256k1 configure (Pieter Wuille)
86dbc4d075decb82fbba837aaa283cf0561897ad Squashed 'src/secp256k1/' changes from be8d9c262f..0559fc6e41 (Pieter Wuille)

Pull request description:

  The motivation for this bump is getting rid of a cast in `CKey::SignSchnorr`; the `aux_rand` argument isn't modified by the `secp256k1_schnorrsig_sign` function, but was marked as non-`const` anyway. This is fixed now (bitcoin-core/secp256k1#966), and the cast is removed in this PR.

  There are a few other relevant changes:
  * (bitcoin-core/secp256k1#956): replaces a runtime-computed table with a precomputed one; this adds arouns 1 MiB to the binary size, but is a step towards significantly simplifying the API. If 1 MiB is too much, it can be reduced by 2 or 4 (or more) for a slight verification performance reduction.
  * (bitcoin-core/secp256k1#983): removes (test/bench only) OpenSSL support entirely, removing the need to pass `--disable-openssl-tests` (see #23314).
  * (bitcoin-core/secp256k1#810): mild performance increase for 64-bit non-x86 platforms.
  * (bitcoin-core/secp256k1#1002): Make aux_rnd32==NULL behave identical to 0x0000..00 (which impacts BIP341/BIP342 signing in Bitcoin Core, making it more strictly BIP340 compliant, though not in a manner that affects security).

ACKs for top commit:
  fanquake:
    ACK 314195c8be3bd7db0d5817c4fb3aa85c84363ce9 - this includes a nice simplification to the lilbsecp build system (and thus our build system), and fixes issues like #22854. Did a Guix build on x86 (above), as well as a build on arm64 (except for the arm64 host):

Tree-SHA512: 0e048390fc148fbbdf5b98d9cce8c71067564e7d69d97b68347808a9bc45a04f4fc653c392c880d79d5d8b9cf282195520955581ac4f1595f6a948080cf5949d

1 files changed, 0 insertions, 125 deletions

diff --git a/src/secp256k1/build-aux/m4/ax_prog_cc_for_build.m4 b/src/secp256k1/build-aux/m4/ax_prog_cc_for_build.m4
deleted file mode 100644
index 7bcbf3200c..0000000000
--- a/src/secp256k1/build-aux/m4/ax_prog_cc_for_build.m4
+++ /dev/null
@@ -1,125 +0,0 @@
-# ===========================================================================
-#   https://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_PROG_CC_FOR_BUILD
-#
-# DESCRIPTION
-#
-#   This macro searches for a C compiler that generates native executables,
-#   that is a C compiler that surely is not a cross-compiler. This can be
-#   useful if you have to generate source code at compile-time like for
-#   example GCC does.
-#
-#   The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
-#   needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
-#   The value of these variables can be overridden by the user by specifying
-#   a compiler with an environment variable (like you do for standard CC).
-#
-#   It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object
-#   file extensions for the build platform, and GCC_FOR_BUILD to `yes' if
-#   the compiler we found is GCC. All these variables but GCC_FOR_BUILD are
-#   substituted in the Makefile.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Paolo Bonzini <bonzini@gnu.org>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved. This file is offered as-is, without any
-#   warranty.
-
-#serial 8
-
-AU_ALIAS([AC_PROG_CC_FOR_BUILD], [AX_PROG_CC_FOR_BUILD])
-AC_DEFUN([AX_PROG_CC_FOR_BUILD], [dnl
-AC_REQUIRE([AC_PROG_CC])dnl
-AC_REQUIRE([AC_PROG_CPP])dnl
-AC_REQUIRE([AC_EXEEXT])dnl
-AC_REQUIRE([AC_CANONICAL_HOST])dnl
-
-dnl Use the standard macros, but make them use other variable names
-dnl
-pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
-pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
-pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
-pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
-pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
-pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
-pushdef([ac_cv_objext], ac_cv_build_objext)dnl
-pushdef([ac_exeext], ac_build_exeext)dnl
-pushdef([ac_objext], ac_build_objext)dnl
-pushdef([CC], CC_FOR_BUILD)dnl
-pushdef([CPP], CPP_FOR_BUILD)dnl
-pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
-pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
-pushdef([LDFLAGS], LDFLAGS_FOR_BUILD)dnl
-pushdef([host], build)dnl
-pushdef([host_alias], build_alias)dnl
-pushdef([host_cpu], build_cpu)dnl
-pushdef([host_vendor], build_vendor)dnl
-pushdef([host_os], build_os)dnl
-pushdef([ac_cv_host], ac_cv_build)dnl
-pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
-pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
-pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
-pushdef([ac_cv_host_os], ac_cv_build_os)dnl
-pushdef([ac_cpp], ac_build_cpp)dnl
-pushdef([ac_compile], ac_build_compile)dnl
-pushdef([ac_link], ac_build_link)dnl
-
-save_cross_compiling=$cross_compiling
-save_ac_tool_prefix=$ac_tool_prefix
-cross_compiling=no
-ac_tool_prefix=
-
-AC_PROG_CC
-AC_PROG_CPP
-AC_EXEEXT
-
-ac_tool_prefix=$save_ac_tool_prefix
-cross_compiling=$save_cross_compiling
-
-dnl Restore the old definitions
-dnl
-popdef([ac_link])dnl
-popdef([ac_compile])dnl
-popdef([ac_cpp])dnl
-popdef([ac_cv_host_os])dnl
-popdef([ac_cv_host_vendor])dnl
-popdef([ac_cv_host_cpu])dnl
-popdef([ac_cv_host_alias])dnl
-popdef([ac_cv_host])dnl
-popdef([host_os])dnl
-popdef([host_vendor])dnl
-popdef([host_cpu])dnl
-popdef([host_alias])dnl
-popdef([host])dnl
-popdef([LDFLAGS])dnl
-popdef([CPPFLAGS])dnl
-popdef([CFLAGS])dnl
-popdef([CPP])dnl
-popdef([CC])dnl
-popdef([ac_objext])dnl
-popdef([ac_exeext])dnl
-popdef([ac_cv_objext])dnl
-popdef([ac_cv_exeext])dnl
-popdef([ac_cv_prog_cc_g])dnl
-popdef([ac_cv_prog_cc_cross])dnl
-popdef([ac_cv_prog_cc_works])dnl
-popdef([ac_cv_prog_gcc])dnl
-popdef([ac_cv_prog_CPP])dnl
-
-dnl Finally, set Makefile variables
-dnl
-BUILD_EXEEXT=$ac_build_exeext
-BUILD_OBJEXT=$ac_build_objext
-AC_SUBST(BUILD_EXEEXT)dnl
-AC_SUBST(BUILD_OBJEXT)dnl
-AC_SUBST([CFLAGS_FOR_BUILD])dnl
-AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
-AC_SUBST([LDFLAGS_FOR_BUILD])dnl
-])