perf: Make perf build for x86 with UAPI disintegration applied

Make perf build for x86 once the UAPI disintegration patches for that arch
have been applied by adding the appropriate -I flags - in the right order -
and then converting some #includes that use ../.. notation to find main kernel
headerfiles to use <asm/foo.h> and <linux/foo.h> instead.

Note that -Iarch/foo/include/uapi is present _before_ -Iarch/foo/include.
This makes sure we get the userspace version of the pt_regs struct.  Ideally,
we wouldn't have the latter -I flag at all, but unfortunately we want
asm/svm.h and asm/vmx.h in builtin-kvm.c and these aren't part of the UAPI -
at least not for x86.  I wonder if the bits outside of the __KERNEL__ guards
*should* be transferred there.

I note also that perf seems to do its dependency handling manually by listing
all the header files it might want to use in LIB_H in the Makefile.  Can this
be changed to use -MD?

Note that to do make this work, we need to export and UAPI disintegrate
linux/hw_breakpoint.h, which I think should've been exported previously so that
perf can access the bits.  We have to do this in the same patch to maintain
bisectability.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/tools/perf/util/parse-events-test.c b/tools/perf/util/parse-events-test.c
index 516ecd9..6ef213b 100644
--- a/tools/perf/util/parse-events-test.c
+++ b/tools/perf/util/parse-events-test.c
@@ -3,7 +3,7 @@
 #include "evsel.h"
 #include "evlist.h"
 #include "sysfs.h"
-#include "../../../include/linux/hw_breakpoint.h"
+#include <linux/hw_breakpoint.h>
 
 #define TEST_ASSERT_VAL(text, cond) \
 do { \