Downgrade Autoconf requirement to version 2.68 (#922)

* Downgrade Autoconf requirement to version 2.68

* CI: remove redundant Autoconf install scripts

.ci/install.sh

@@ -37,39 +37,6 @@ else
     sudo apt-get update
     sudo apt install libltdl-dev zip
 
-    shopt -s inherit_errexit   # propagate failure out of subshells (bash >= 4.4)
-
-    URL=https://ftpmirror.gnu.org/autoconf/autoconf-2.72.tar.gz
-    MAX_TRIES=5
-    BACKOFF=2                  # seconds; will double every attempt
-
-    attempt=1
-    while (( attempt <= MAX_TRIES )); do
-        echo "➡️  Attempt ${attempt}/${MAX_TRIES}"
-        if wget --retry-connrefused \
-                --waitretry=1 \
-                --read-timeout=20 \
-                --timeout=15 \
-                -qO-  "$URL" \
-                | tar -xzv; then
-            echo "✅  Success on attempt ${attempt}"
-            break
-        fi
-
-        echo "⚠️  Download or extract failed, retrying in ${BACKOFF}s…"
-        sleep "$BACKOFF"
-        BACKOFF=$(( BACKOFF * 2 ))
-        (( attempt++ ))
-    done
-
-    if (( attempt > MAX_TRIES )); then
-        echo "❌  Exhausted retries ($MAX_TRIES) – aborting." >&2
-        exit 1
-    fi
-
-    mkdir -p ~/i
-    (cd autoconf-2.72; ./configure --prefix=$HOME/i; make; make install)
-
     case $HOST in
 	      mips64el-linux-gnu | sparc64-linux-gnu)
         ;;

configure.ac

@@ -1,6 +1,6 @@
 dnl Process this with autoconf to create configure
 
-AC_PREREQ([2.72])
+AC_PREREQ([2.68])
 
 AC_INIT([libffi],[3.5.0],[http://github.com/libffi/libffi/issues])
 AC_CONFIG_HEADERS([fficonfig.h])
@@ -94,10 +94,6 @@ m4_warn([obsolete],
 [The preprocessor macro `STDC_HEADERS' is obsolete.
   Except in unusual embedded environments, you can safely include all
   ISO C90 headers unconditionally.])dnl
-# Autoupdate added the next two lines to ensure that your configure
-# script's behavior did not change.  They are probably safe to remove.
-AC_CHECK_INCLUDES_DEFAULT
-AC_PROG_EGREP
 
 AC_CHECK_FUNCS(memcpy)
 AC_CHECK_HEADERS(alloca.h)

testsuite/emscripten/build.sh

@@ -38,13 +38,6 @@ export EM_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
 # Specific variables for cross-compilation
 export CHOST="wasm32-unknown-linux" # wasm32-unknown-emscripten
 
-wget --retry-connrefused --waitretry=1 --read-timeout=20 --timeout=15 -t 0 -qO - https://ftpmirror.gnu.org/autoconf/autoconf-2.72.tar.gz | tar -xvzf -
-mkdir -p ~/i
-(cd autoconf-2.72; ./configure --prefix=$HOME/i; make; make install)
-
-# Special build tools are here...
-export PATH=$HOME/i/bin:$PATH
-
 autoreconf -fiv
 emconfigure ./configure --host=$CHOST --prefix="$TARGET" --enable-static --disable-shared --disable-dependency-tracking \
   --disable-builddir --disable-multi-os-directory --disable-raw-api --disable-docs

testsuite/emscripten/node-tests.sh

@@ -13,13 +13,6 @@ export LDFLAGS="-sEXPORTED_FUNCTIONS=_main,_malloc,_free -sALLOW_TABLE_GROWTH -s
 # Specific variables for cross-compilation
 export CHOST="wasm32-unknown-linux" # wasm32-unknown-emscripten
 
-wget --retry-connrefused --waitretry=1 --read-timeout=20 --timeout=15 -t 0 -qO - https://ftpmirror.gnu.org/autoconf/autoconf-2.72.tar.gz | tar -xvzf -
-mkdir -p ~/i
-(cd autoconf-2.72; ./configure --prefix=$HOME/i; make; make install)
-
-# Special build tools are here...
-export PATH=$HOME/i/bin:$PATH
-
 autoreconf -fiv
 emconfigure ./configure --prefix="$(pwd)/target" --host=$CHOST --enable-static --disable-shared \
   --disable-builddir --disable-multi-os-directory --disable-raw-api --disable-docs ||