Revert gcc check to reenable cross compiling

CHANGES

@@ -61,7 +61,7 @@ corrections:
 	Test: IGNOREEOF_REV
 	Thanks to Franz Fasching for reporting this bug.
 
-	Address SYSTEM, when terminating, shutted down its parent addresses,
+	Address SYSTEM, when terminating, shut down its parent addresses,
 	e.g. an SSL connection which the parent assumed to still be active.
 	Test: SYSTEM_SHUTDOWN
 
@@ -93,6 +93,10 @@ porting:
 	Socat included <sys/poll.h> instead of POSIX <poll.h>
 	Thanks to John Spencer for reporting this issue.
 
+	Version 1.7.2.4 changed the check for gcc in configure.ac; this
+	broke cross compiling. The particular check gets reverted.
+	Thanks to Ross Burton and Danomi Manchego for reporting this issue.
+
 testing:
 	Do not distribute testcert.conf with socat source but generate it
 	(and new testcert6.conf) during test.sh run.

configure.in

@@ -41,7 +41,7 @@ AC_CHECK_PROG(AR, ar, ar, gar)
 # fail
 AC_LANG_COMPILER_REQUIRE()
 
-if test "$CC" = "gcc"; then
+if test "$GCC" = yes; then
    CFLAGS="$CFLAGS -D_GNU_SOURCE -Wall -Wno-parentheses"
    ERRONWARN="-Werror -O0"
 elif test "$CC" = "clang"; then

test.sh

@@ -179,8 +179,8 @@ case "$UNAME" in
 *)
     PTYOPTS="echo=0,opost=0"
     #PTYOPTS2="raw,echo=0"
-    #PTYOPTS2="cfmakeraw"
-    PTYOPTS2="rawer"
+    PTYOPTS2="cfmakeraw"
+    #PTYOPTS2="rawer"
     ;;
 esac