Added some support for GCC 5+.

configure

@@ -823,7 +823,7 @@ else
 			get_build_tool_path STRIP_$targetArch ${crossToolsPrefix}strip
 
 			case `get_variable HAIKU_GCC_RAW_VERSION_$targetArch` in
-				4.*)
+				4.*|5.*|6.*)
 					get_build_tool_path ELFEDIT_$targetArch \
 						${crossToolsPrefix}elfedit
 				;;

headers/os/BeBuild.h

@@ -45,7 +45,7 @@
 
 #if __GNUC__ == 2
 #	define B_HAIKU_ABI					B_HAIKU_ABI_GCC_2_HAIKU
-#elif __GNUC__ == 4
+#elif __GNUC__ == 4 || __GNUC__ == 5 || __GNUC__ == 6
 #	define B_HAIKU_ABI					B_HAIKU_ABI_GCC_4
 #else
 #	error Unsupported gcc version!

headers/private/kernel/util/AutoLock.h

@@ -130,9 +130,9 @@ typedef AutoLocker<spinlock, SpinLocking> SpinLocker;
 
 class InterruptsSpinLocking {
 public:
-// NOTE: work-around for annoying GCC 4 "fState may be used uninitialized"
+// NOTE: work-around for annoying GCC 4+ "fState may be used uninitialized"
 // warning.
-#if __GNUC__ == 4
+#if __GNUC__ >= 4
 	InterruptsSpinLocking()
 		:
 		fState(0)