Fixed Mac OS X 10.7 as a build platform (for GCC 4).

* Use gcc and g++ rather than cc and c++, as the latter now point to
  clang with recent Xcode versions and compilation of the host tools
  fail for various reasons with it.
* Replace the case-sensitive filesystem check with a more basic one,
  as diskutil no longer supports the behaviour of getting info for the
  volume that any path is on.
* Updated ReadMe with a correct list of prerequisites for OS X.
* GCC 2 builds are still broken due to a strange error that only
  occurs with a GCC 2 built on OS X 10.7

ReadMe

@@ -75,6 +75,13 @@ The following darwin ports need to be installed:
  * libiconv
  * gnuregex
  * gsed
+ * cdrtools
+ * yasm
+ * wget
+ * less
+ * mpfr
+ * gmp
+ * libmpc
 
 More information about individual distributions of Linux and BSD can be found
 at http://haiku-os.org/guides/building/pre-reqs

build/jam/BuildSetup

@@ -609,6 +609,13 @@ if $(HOST_PLATFORM) = linux || $(HOST_PLATFORM) = freebsd
 	}
 }
 
+# On recent versions of OS X cc and c++ point to clang, which fails to
+# compile some of the host tools. As a workaround, force use of GCC.
+if $(HOST_PLATFORM) = darwin {
+	HOST_CC = gcc ;
+	HOST_C++ = g++ ;
+}
+
 if $(HOST_PLATFORM) = cygwin {
 	HOST_LINKFLAGS += -Xlinker --allow-multiple-definition -Xlinker
 		--enable-auto-import ;

configure

@@ -471,15 +471,18 @@ for sfdiskDir in /sbin /usr/sbin /usr/local/sbin ; do
 	fi
 done
 
-# check for case-sensitive filesystem if on darwin
-if [ $HOST_PLATFORM = "darwin" ]; then
-	diskutil info $(pwd)/.. | grep -i "case-sensitive" > /dev/null
-	if [ $? != 0 ]; then
-		echo "You need a case-sensitive file-system to build Haiku."
-		echo "Please see the following guide on how to set one up:"
-		echo "http://haiku-os.org/documents/dev/how_to_build_haiku_on_mac_os_x"
-		exit 1
+# check for case-sensitive filesystem
+mkdir haikuCaseTest 2>/dev/null
+mkdir haikucasetest 2>/dev/null
+caseInsensitive=$?
+rm -df haikuCaseTest haikucasetest
+if [ $caseInsensitive != 0 ]; then
+	echo "You need a case-sensitive file-system to build Haiku."
+	if [ $HOST_PLATFORM = "darwin" ]; then
+		echo "You can create a case-sensitive disk image using Disk Utility and use"
+		echo "it to store the Haiku sources on."
 	fi
+	exit 1
 fi
 
 # create output directory