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)
</table>
<div class='path'>path: <a href='/guix/log/?id=4089d7920fc5f27fefdde6b0fec17f3224e62377'>root</a>/<a href='/guix/log/gnu?id=4089d7920fc5f27fefdde6b0fec17f3224e62377'>gnu</a>/<a href='/guix/log/gnu/packages?id=4089d7920fc5f27fefdde6b0fec17f3224e62377'>packages</a>/<a href='/guix/log/gnu/packages/haskell.scm?id=4089d7920fc5f27fefdde6b0fec17f3224e62377'>haskell.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/packages/haskell.scm?id=4089d7920fc5f27fefdde6b0fec17f3224e62377&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-06-01 15:08:15 +0200'>2020-06-01</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=f20d1cfb51ed14f325da000406807076323f70bc'>gnu: ghc-7: Clean up package definition.</a><span class='msg-avail'>...</span></td><td>Jakub Kądziołka</td></tr>
<tr><td><span title='2020-05-13 09:30:26 +0300'>2020-05-13</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=3c986a7dc268756c097212de958f046b29b76c1b'>mailmap: Update entries for Nikita.</a><span class='msg-avail'>...</span></td><td>nikita</td></tr>
<tr><td><span title='2020-03-24 18:02:44 +0100'>2020-03-24</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=eac54126fbb0712a436eaa1b152a55efb32046ab'>gnu: GHC: Enable RUNPATH validation.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-03-24 18:02:43 +0100'>2020-03-24</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=f4e183320515e00a68912d98e1f8367c72886527'>gnu: ghc@8.0: Remove obsolete patch.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-03-24 18:02:43 +0100'>2020-03-24</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=c75db693713e74a632bafe849de68a87ee7e34eb'>gnu: ghc: Really disable test that fails with glibc 2.30 and later.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-03-23 19:42:56 +0100'>2020-03-23</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=2e9c43aa9adac2bd6bcf92373d1cf9f322afa5a3'>gnu: GHC: Disable test that fails with glibc 2.30 and later.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-03-23 16:33:06 +0100'>2020-03-23</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=c711b6abdb7fc740b37e95596eab2b1b9aba0e1d'>gnu: ghc@8.4: Update to 8.4.4.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-03-23 16:32:44 +0100'>2020-03-23</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=a057b88124a1b6b6401a2d0c502afc352a10b448'>gnu: ghc@8.4: Remove redundant inputs.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2019-11-20 20:47:48 -0500'>2019-11-20</span></td><td><a href='/guix/commit/gnu/packages/haskell.scm?id=064a967ba0480d35d706f96e8aa5bb86f0947b4d'>gnu: Use GHC 8.6.5 as the main Haskell compiler.</a><span class='msg-avail'>...</span></td><td>Timothy Sample</td></tr>