Add support for gcc v3.x compilers.

Suppress __attribute__((externally_visible)) when no -fwhole-program
Add switch hack for compilers without -fno-jump-tables
Define memcpy() function (for compilers without -minline-all-stringops).
Define call16_simpint as a macro (a param needs to be inlined).
Make sure s3_resume is only defined in 32bit mode.
diff --git a/tools/test-gcc.sh b/tools/test-gcc.sh
index c354ec3..55f359f 100755
--- a/tools/test-gcc.sh
+++ b/tools/test-gcc.sh
@@ -11,10 +11,9 @@
 # Test for "-fwhole-program"
 $CC -fwhole-program -S -o /dev/null -xc /dev/null > /dev/null 2>&1
 if [ $? -ne 0 ]; then
-    echo "This version of gcc does not support -fwhole-program." > /dev/fd/2
-    echo "Please upgrade to gcc v4.1 or later" > /dev/fd/2
-    echo -1
-    exit 1
+    echo "  Working around no -fwhole-program" > /dev/fd/2
+    echo 1
+    exit 0
 fi
 
 # Test if "visible" variables are marked global.