From: Jan Engelhardt <jengelh@inai.de>
Date: 2016-06-30 13:18:23.962908776 +0200

build: resolve autoreconf warnings

GNUmakefile.am:33: warning: compiling 'sassc.c' with per-target flags requires 'AM_PROG_CC_C_O' in 'configure.ac'
/usr/share/automake-1.13/am/ltlibrary.am: archiver requires 'AM_PROG_AR' in 'configure.ac'

Adding AM_PROG_CC_C_O also requires that no AC_PROG_CC follows it.
Remove the duplicated test, then.

---
 configure.ac |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: libsass-3.3.2/configure.ac
===================================================================
--- libsass-3.3.2.orig/configure.ac
+++ libsass-3.3.2/configure.ac
@@ -18,6 +18,7 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_R
 
 # Checks for programs.
 AC_PROG_CC
+AM_PROG_CC_C_O
 AC_PROG_CXX
 AC_LANG_PUSH([C])
 AC_LANG_PUSH([C++])
@@ -30,6 +31,7 @@ if test "x$is_mingw32" != "xyes"; then
   AC_CHECK_TOOL([DLLWRAP], [dllwrap], [false])
   AC_CHECK_TOOL([WINDRES], [windres], [false])
 fi
+m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 LT_INIT([dlopen])
 
 # Checks for header files.
@@ -58,7 +60,6 @@ if test "x$is_mingw32" != "xyes"; then
 fi
 
 if test "x$enable_tests" = "xyes"; then
-  AC_PROG_CC
   AC_PROG_AWK
   # test need minitest gem
   AC_PATH_PROG(RUBY, [ruby])