systemtap: improve reproducibility

- Fix build path issue of .pyc files:
  Supply "--root" directory to the "install" command.

- Fix build path issue of c++ object files:
  Use relative dir to include header string_ref.

- Fix build path issue of c library generated by distutils:
  Add OE's CFLAGS which contains `-fdebug-prefix-map' options
  to setup.py

[YOCTO #12528]

(From OE-Core rev: 806a8626c3fb5020666152b295f12541f5f61ffd)

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-kernel/systemtap/systemtap_git.bb

@@ -3,6 +3,8 @@ HOMEPAGE = "https://sourceware.org/systemtap/"
 
 require systemtap_git.inc
 
+SRC_URI += "file://0001-improve-reproducibility-for-c-compiling.patch"
+
 DEPENDS = "elfutils"
 
 EXTRA_OECONF += "--with-libelf=${STAGING_DIR_TARGET} --without-rpm \
@@ -25,6 +27,12 @@ PACKAGECONFIG[python3-probes] = "--with-python3-probes,--without-python3-probes,
 
 inherit autotools gettext pkgconfig distutils3-base
 
+do_configure_prepend () {
+    # Improve reproducibility for c++ object files
+    reltivepath="${@os.path.relpath(d.getVar('STAGING_INCDIR'), d.getVar('S'))}"
+    sed -i "s:@RELATIVE_STAGING_INCDIR@:$reltivepath:g" ${S}/stringtable.h
+}
+
 do_install_append () {
    if [ ! -f ${D}${bindir}/stap ]; then
       # translator disabled case, need to leave only minimal runtime