Remove fixed search paths from autotools.

--- a/m4/package_utilies.m4	1970-01-01 01:00:01.000000000 +0100
+++ b/m4/package_utilies.m4	2020-07-07 12:41:48.871661042 +0200
@@ -23,32 +23,32 @@
     AC_PACKAGE_NEED_UTILITY($1, "$cc", cc, [C compiler])
 
     if test -z "$MAKE"; then
-        AC_PATH_PROG(MAKE, gmake,, /usr/bin:/usr/freeware/bin)
+        AC_PATH_PROG(MAKE, gmake)
     fi
     if test -z "$MAKE"; then
-        AC_PATH_PROG(MAKE, make,, /usr/bin)
+        AC_PATH_PROG(MAKE, make)
     fi
     make=$MAKE
     AC_SUBST(make)
     AC_PACKAGE_NEED_UTILITY($1, "$make", make, [GNU make])
 
     if test -z "$LIBTOOL"; then
-	AC_PATH_PROG(LIBTOOL, glibtool,, /usr/bin)
+	AC_PATH_PROG(LIBTOOL, glibtool)
     fi
     if test -z "$LIBTOOL"; then
-	AC_PATH_PROG(LIBTOOL, libtool,, /usr/bin:/usr/local/bin:/usr/freeware/bin)
+	AC_PATH_PROG(LIBTOOL, libtool)
     fi
     libtool=$LIBTOOL
     AC_SUBST(libtool)
     AC_PACKAGE_NEED_UTILITY($1, "$libtool", libtool, [GNU libtool])
 
     if test -z "$TAR"; then
-        AC_PATH_PROG(TAR, tar,, /usr/freeware/bin:/bin:/usr/local/bin:/usr/bin)
+        AC_PATH_PROG(TAR, tar)
     fi
     tar=$TAR
     AC_SUBST(tar)
     if test -z "$ZIP"; then
-        AC_PATH_PROG(ZIP, gzip,, /bin:/usr/local/bin:/usr/freeware/bin)
+        AC_PATH_PROG(ZIP, gzip)
     fi
 
     zip=$ZIP
@@ -61,25 +61,25 @@
     AC_SUBST(makedepend)
 
     if test -z "$AWK"; then
-        AC_PATH_PROG(AWK, awk,, /bin:/usr/bin)
+        AC_PATH_PROG(AWK, awk)
     fi
     awk=$AWK
     AC_SUBST(awk)
 
     if test -z "$SED"; then
-        AC_PATH_PROG(SED, sed,, /bin:/usr/bin)
+        AC_PATH_PROG(SED, sed)
     fi
     sed=$SED
     AC_SUBST(sed)
 
     if test -z "$ECHO"; then
-        AC_PATH_PROG(ECHO, echo,, /bin:/usr/bin)
+        AC_PATH_PROG(ECHO, echo)
     fi
     echo=$ECHO
     AC_SUBST(echo)
 
     if test -z "$SORT"; then
-        AC_PATH_PROG(SORT, sort,, /bin:/usr/bin)
+        AC_PATH_PROG(SORT, sort)
     fi
     sort=$SORT
     AC_SUBST(sort)
path'>path: <a href='/guix/log/?id=d51b94abfab11ef4ee1d7a6fdd64257c213e0fba'>root</a>/<a href='/guix/log/gnu?id=d51b94abfab11ef4ee1d7a6fdd64257c213e0fba'>gnu</a>/<a href='/guix/log/gnu/build?id=d51b94abfab11ef4ee1d7a6fdd64257c213e0fba'>build</a>/<a href='/guix/log/gnu/build/install.scm?id=d51b94abfab11ef4ee1d7a6fdd64257c213e0fba'>install.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/build/install.scm?id=d51b94abfab11ef4ee1d7a6fdd64257c213e0fba&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-02-19 18:42:12 +0100'>2024-02-19</span></td><td><a href='/guix/commit/gnu/build/install.scm?id=27ee6f06d0ecab58ca3b739c911bacefda440177'>services: activation: Ensure /run existence.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/activation.scm (activation-script): Ensure /var/run existence.
* gnu/build/install.scm (evaluate-populate-directive)
[directives]: Remove directory /run.

Change-Id: I19ca8e7605c0cff598ab89077a94e20390ba27b0
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Nicolas Graves</td></tr>
<tr><td><span title='2024-02-19 18:41:47 +0100'>2024-02-19</span></td><td><a href='/guix/commit/gnu/build/install.scm?id=e73db355b127b9ca2b5339f645f2d3eb6929531f'>services: activation: Ensure /var/run existence.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services.scm (activation-script): Ensure /var/run existence.
* gnu/build/install.scm (evaluate-populate-directive)
[directives]: Remove directory /var/run.

Change-Id: I5fb93d33b6b1f045f1e5ba206b9b0b74b5184260
Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Nicolas Graves</td></tr>