Add elfctl to toolchain.

Add elfctl program to toolchain to allow modifying ELF feature flags
during system build.

Submitted by: Dawid Gorecki <dgr@semihalf.com>
Obtained from: Semihalf
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D29552

Makefile.inc1

@@ -199,7 +199,7 @@ MK_SYSTEM_LINKER=	no
 .if defined(CROSS_TOOLCHAIN_PREFIX)
 CROSS_BINUTILS_PREFIX?=${CROSS_TOOLCHAIN_PREFIX}
 .endif
-XBINUTILS=	AS AR LD NM OBJCOPY RANLIB SIZE STRINGS STRIPBIN
+XBINUTILS=	AS AR ELFCTL LD NM OBJCOPY RANLIB SIZE STRINGS STRIPBIN
 .for BINUTIL in ${XBINUTILS}
 .if defined(CROSS_BINUTILS_PREFIX) && \
     exists(${CROSS_BINUTILS_PREFIX}/${${BINUTIL}})
@@ -794,8 +794,8 @@ HMAKE+=		PATH=${TMPPATH} METALOG=${METALOG} -DNO_ROOT
 
 CROSSENV+=	CC="${XCC} ${XCFLAGS}" CXX="${XCXX} ${XCXXFLAGS} ${XCFLAGS}" \
 		CPP="${XCPP} ${XCFLAGS}" \
-		AS="${XAS}" AR="${XAR}" LD="${XLD}" LLVM_LINK="${XLLVM_LINK}" \
-		NM=${XNM} OBJCOPY="${XOBJCOPY}" \
+		AS="${XAS}" AR="${XAR}" ELFCTL="${XELFCTL}" LD="${XLD}" \
+		LLVM_LINK="${XLLVM_LINK}" NM=${XNM} OBJCOPY="${XOBJCOPY}" \
 		RANLIB=${XRANLIB} STRINGS=${XSTRINGS} \
 		SIZE="${XSIZE}" STRIPBIN="${XSTRIPBIN}"
 
@@ -2600,6 +2600,7 @@ _dtrace_tools= cddl/lib/libctf cddl/lib/libspl cddl/usr.bin/ctfconvert \
 .if ${MK_ELFTOOLCHAIN_BOOTSTRAP} != "no"
 _elftctools=	lib/libelftc \
 		lib/libpe \
+		usr.bin/elfctl \
 		usr.bin/objcopy \
 		usr.bin/nm \
 		usr.bin/size \
@@ -2613,6 +2614,7 @@ _elftctools+=	usr.bin/addr2line
 # the target (for at least crunchide).
 _elftctools=	lib/libelftc \
 		lib/libpe \
+		usr.bin/elfctl \
 		usr.bin/objcopy
 .endif
 

share/mk/sys.mk

@@ -210,6 +210,8 @@ ECHODIR		?=	true
 .endif
 .endif
 
+ELFCTL		?=	elfctl
+
 .if ${.MAKEFLAGS:M-N}
 # bmake -N is supposed to skip executing anything but it does not skip
 # exeucting '+' commands.  The '+' feature is used where .MAKE