tools: do not include scripts/Kbuild.include

Since commit 57fd251c7896 ("kbuild: split cc-option and friends to
scripts/Makefile.compiler"), some kselftests fail to build.

The tools/ directory opted out Kbuild, and went in a different
direction. People copied scripts and Makefiles to the tools/ directory
to create their own build system.

tools/build/Build.include mimics scripts/Kbuild.include, but some
tool Makefiles include the Kbuild one to import a feature that is
missing in tools/build/Build.include:

- Commit ec04aa3ae87b ("tools/thermal: tmon: use "-fstack-protector"
only if supported") included scripts/Kbuild.include from
tools/thermal/tmon/Makefile to import the cc-option macro.

- Commit c2390f16fc5b ("selftests: kvm: fix for compilers that do
not support -no-pie") included scripts/Kbuild.include from
tools/testing/selftests/kvm/Makefile to import the try-run macro.

- Commit 9cae4ace80ef ("selftests/bpf: do not ignore clang
failures") included scripts/Kbuild.include from
tools/testing/selftests/bpf/Makefile to import the .DELETE_ON_ERROR
target.

- Commit 0695f8bca93e ("selftests/powerpc: Handle Makefile for
unrecognized option") included scripts/Kbuild.include from
tools/testing/selftests/powerpc/pmu/ebb/Makefile to import the
try-run macro.

Copy what they need into tools/build/Build.include, and make them
include it instead of scripts/Kbuild.include.

Link: https://lore.kernel.org/lkml/[e-mail]/
Fixes: 57fd251c7896 ("kbuild: split cc-option and friends to scripts/Makefile.compiler")
Reported-by: Janosch Frank <[e-mail]>
Reported-by: Christian Borntraeger <[e-mail]>
Signed-off-by: Masahiro Yamada <[e-mail]>
Tested-by: Christian Borntraeger <[e-mail]>
Acked-by: Yonghong Song <[e-mail]>

tools/build/Build.include

···
 ## HOSTCC C flags
 
 host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(KBUILD_HOSTCFLAGS) -D"BUILD_STR(s)=\#s" $(HOSTCFLAGS_$(basetarget).o) $(HOSTCFLAGS_$(obj))
+
+# output directory for tests below
+TMPOUT = .tmp_$$$$
+
+# try-run
+# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise)
+# Exit code chooses option. "$$TMP" serves as a temporary file and is
+# automatically cleaned up.
+try-run = $(shell set -e;		\
+	TMP=$(TMPOUT)/tmp;		\
+	mkdir -p $(TMPOUT);		\
+	trap "rm -rf $(TMPOUT)" EXIT;	\
+	if ($(1)) >/dev/null 2>&1;	\
+	then echo "$(2)";		\
+	else echo "$(3)";		\
+	fi)
+
+# cc-option
+# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
+cc-option = $(call try-run, \
+	$(CC) -Werror $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+
+# delete partially updated (i.e. corrupted) files on error
+.DELETE_ON_ERROR:

tools/testing/selftests/bpf/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
-include ../../../../scripts/Kbuild.include
+include ../../../build/Build.include
 include ../../../scripts/Makefile.arch
 include ../../../scripts/Makefile.include
 

tools/testing/selftests/kvm/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
-include ../../../../scripts/Kbuild.include
+include ../../../build/Build.include
 
 all:
 

tools/testing/selftests/powerpc/pmu/ebb/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
-include ../../../../../../scripts/Kbuild.include
+include ../../../../../build/Build.include
 
 noarg:
 	$(MAKE) -C ../../

tools/thermal/tmon/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 # We need this for the "cc-option" macro.
-include ../../../scripts/Kbuild.include
+include ../../build/Build.include
 
 VERSION = 1.0