allow stripping of generated symbols under CONFIG_KALLSYMS_ALL

Building upon parts of the module stripping patch, this patch
introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y.
Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of
CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64)
kernels I tested with.

The patch also does away with the need to special case the kallsyms-
internal symbols by making them available even in the first linking
stage.

While it is a generated file, the patch includes the changes to
scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure
here is.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/init/Kconfig b/init/Kconfig
index f763762..0f5af40 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -588,6 +588,13 @@
 
 	   Say N.
 
+config KALLSYMS_STRIP_GENERATED
+	bool "Strip machine generated symbols from kallsyms"
+	depends on KALLSYMS_ALL
+	default y
+	help
+	  Say N if you want kallsyms to retain even machine generated symbols.
+
 config KALLSYMS_EXTRA_PASS
 	bool "Do an extra kallsyms pass"
 	depends on KALLSYMS