[PATCH] add compiler-gcc4.h

With the release of gcc 4.0 being only a few months away and people
already tring compiling with it, it's time for adding a compiler-gcc4.h .

This patch contains the following changes:
- remove compiler-gcc+.h
- compiler-gcc4.h: new file based on a corrected compiler-gcc+.h
- compiler.h: include compiler-gcc4.h for gcc 4
- compiler.h: #error for gcc > 4
- compiler-gcc3.h: remove __compiler_offsetof (there will never be a
                                               gcc 3.5)
                   small indention corrections

I've tested the compilation with both gcc 3.4.4 and a recent gcc 4.0 
snapshot from Debian experimental.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/compiler-gcc3.h

@@ -25,10 +25,8 @@
 #if __GNUC_MINOR__ >= 1
 #define  noinline		__attribute__((noinline))
 #endif
+
 #if __GNUC_MINOR__ >= 4
 #define __must_check		__attribute__((warn_unused_result))
 #endif
 
-#if __GNUC_MINOR__ >= 5
-#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
-#endif

include/linux/compiler-gcc+.h → include/linux/compiler-gcc4.h

 /* Never include this file directly.  Include <linux/compiler.h> instead.  */
 
-/*
- * These definitions are for Ueber-GCC: always newer than the latest
- * version and hence sporting everything plus a kitchen-sink.
- */
+/* These definitions are for GCC v4.x.  */
 #include <linux/compiler-gcc.h>
 
 #define inline			inline		__attribute__((always_inline))
@@ -13,4 +10,7 @@
 #define __attribute_used__	__attribute__((__used__))
 #define __attribute_pure__	__attribute__((pure))
 #define __attribute_const__	__attribute__((__const__))
+#define  noinline		__attribute__((noinline))
 #define __must_check 		__attribute__((warn_unused_result))
+#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
+

include/linux/compiler.h

@@ -34,8 +34,10 @@ extern void __chk_io_ptr(void __iomem *);
 
 #ifdef __KERNEL__
 
-#if __GNUC__ > 3
-# include <linux/compiler-gcc+.h>	/* catch-all for GCC 4, 5, etc. */
+#if __GNUC__ > 4
+#error no compiler-gcc.h file for this gcc version
+#elif __GNUC__ == 4
+# include <linux/compiler-gcc4.h>
 #elif __GNUC__ == 3
 # include <linux/compiler-gcc3.h>
 #elif __GNUC__ == 2