Move to /usr prefix.

- This is much more standard and replaces /image in sysa and is the
  standard in sysc (avoids many issues).
- GCC needs to have a file created for some unknown reason.
- Checksums updated.

sysc/patch-2.7.6/checksums

@@ -0,0 +1 @@
+b887260c73947c5293804f42cbfcd2d48728f7ed395fdfe5ffde0aa96e381fd1  /usr/bin/patch

sysc/patch-2.7.6/import-gnulib.sh

@@ -0,0 +1,76 @@
+#!/bin/sh
+
+# SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+../gnulib-e017871/gnulib-tool --import \
+    --local-dir=gl \
+    --lib=libpatch \
+    --source-base=lib \
+    --m4-base=m4 \
+    --doc-base=doc \
+    --tests-base=tests \
+    --aux-dir=build-aux \
+    --makefile-name=gnulib.mk \
+    --no-conditional-dependencies \
+    --no-libtool \
+    --macro-prefix=gl \
+    argmatch \
+    backupfile \
+    clock-time \
+    diffseq \
+    dirname \
+    dup2 \
+    errno \
+    exitfail \
+    extensions \
+    faccessat \
+    fchmodat \
+    fchownat \
+    fcntl-h \
+    fstatat \
+    full-write \
+    getdate \
+    getopt-gnu \
+    gettime \
+    git-version-gen \
+    gitlog-to-changelog \
+    gnupload \
+    hash \
+    ignore-value \
+    intprops \
+    largefile \
+    linked-list \
+    maintainer-makefile \
+    malloc \
+    manywarnings \
+    memchr \
+    minmax \
+    mkdirat \
+    nstrftime \
+    openat \
+    progname \
+    quotearg \
+    readlinkat \
+    realloc \
+    renameat \
+    setenv \
+    signal \
+    size_max \
+    ssize_t \
+    stat-time \
+    stdbool \
+    stdlib \
+    symlinkat \
+    sys_stat \
+    tempname \
+    time \
+    unistd \
+    unlinkat \
+    update-copyright \
+    utimensat \
+    verror \
+    xalloc \
+    xlist \
+    xmemdup0

sysc/patch-2.7.6/patch-2.7.6.sh

@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+src_prepare() {
+    ../../import-gnulib.sh
+
+    # bison
+    rm lib/parse-datetime.c
+
+    autoreconf -fi
+}
+
+src_configure() {
+    ./configure --prefix="${PREFIX}"
+}
+
+src_compile() {
+    make MAKEINFO=true
+}
+
+src_install() {
+    make MAKEINFO=true DESTDIR="${DESTDIR}" install
+}