Makefile: build testdata using clang-14, 17, 20

A prior commit upgraded the toolchain to this set of LLVM versions.

-mcpu=v3 is now the default in LLVM 20, so specify -mcpu=v2 explicitly to
maintain compatibility with 4.x kernels.

Signed-off-by: Timo Beckers <[email protected]>

Author: ti-mo

Makefile

@@ -1,10 +1,10 @@
 # The development version of clang is distributed as the 'clang' binary,
 # while stable/released versions have a version number attached.
 # Pin the default clang to a stable version.
-CLANG ?= clang-17
-STRIP ?= llvm-strip-17
-OBJCOPY ?= llvm-objcopy-17
-CFLAGS := -O2 -g -Wall -Werror $(CFLAGS)
+CLANG ?= clang-20
+STRIP ?= llvm-strip-20
+OBJCOPY ?= llvm-objcopy-20
+CFLAGS := -O2 -g -Wall -Werror -mcpu=v2 $(CFLAGS)
 
 CI_KERNEL_URL ?= https://github.com/cilium/ci-kernels/raw/master/
 
@@ -25,8 +25,8 @@ IMAGE := $(shell cat ${REPODIR}/testdata/docker/IMAGE)
 VERSION := $(shell cat ${REPODIR}/testdata/docker/VERSION)
 
 TARGETS := \
-	testdata/loader-clang-11 \
 	testdata/loader-clang-14 \
+	testdata/loader-clang-17 \
 	testdata/loader-$(CLANG) \
 	testdata/manyprogs \
 	testdata/btf_map_init \