devel/llvm12: fix openmp library depends

Use base system libelf and don't link with libffi.

Reformat multi-line OPTION_CMAKE_ON variables.

PR:		273801
Co-authored-by:	Ivan Rozhuk <rozhuk.im@gmail.com>

devel/llvm12/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	llvm
 DISTVERSION=	12.0.1
-PORTREVISION=	10
+PORTREVISION=	11
 CATEGORIES=	devel lang
 MASTER_SITES=	https://github.com/llvm/llvm-project/releases/download/llvmorg-${DISTVERSION:S/rc/-rc/}/ \
 		https://${PRE_}releases.llvm.org/${LLVM_RELEASE}/${RCDIR}
@@ -120,19 +120,22 @@ COMPILER_RT_DESC=	Sanitizer libraries
 # An unwind.h is require to build.  I think an in-tree one should be used
 # but this seems to work as a workaround...
 COMPILER_RT_BUILD_DEPENDS=	libunwind>0:devel/libunwind
-COMPILER_RT_CMAKE_ON=	-DCOMPILER_RT_INSTALL_PATH=${LLVM_PREFIX}/lib/clang/${LLVM_RELEASE}
+COMPILER_RT_CMAKE_ON= \
+	-DCOMPILER_RT_INSTALL_PATH=${LLVM_PREFIX}/lib/clang/${LLVM_RELEASE}
 # Allow unwind.h to be found reliably
 COMPILER_RT_USES=	localbase
 COMPILER_RT_PLIST_FILES=${_COMPILER_RT_LIBS:S|^|${_CRTLIBDIR}/|} \
 			${_COMPILER_RT_BLACKLISTS:S|^|${_CRTBLDIR}/|}
-DOCS_BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}sphinx>=0,1:textproc/py-sphinx@${PY_FLAVOR} \
-			${PYTHON_PKGNAMEPREFIX}recommonmark>=0.0.20180530:textproc/py-recommonmark@${PY_FLAVOR}
+DOCS_BUILD_DEPENDS= \
+	${PYTHON_PKGNAMEPREFIX}sphinx>=0,1:textproc/py-sphinx@${PY_FLAVOR} \
+	${PYTHON_PKGNAMEPREFIX}recommonmark>=0.0.20180530:textproc/py-recommonmark@${PY_FLAVOR}
 DOCS_CONFLICTS_BUILD=	cmark
 DOCS_PORTDOCS=		llvm
-DOCS_CMAKE_ON=		-DLLVM_ENABLE_SPHINX=ON \
-			-DSPHINX_EXECUTABLE=${LOCALBASE}/bin/sphinx-build-${PYTHON_VER} \
-			-DSPHINX_WARNINGS_AS_ERRORS=OFF \
-			-DLLVM_BUILD_DOCS=ON
+DOCS_CMAKE_ON= \
+	-DLLVM_ENABLE_SPHINX=ON \
+	-DSPHINX_EXECUTABLE=${LOCALBASE}/bin/sphinx-build-${PYTHON_VER} \
+	-DSPHINX_WARNINGS_AS_ERRORS=OFF \
+	-DLLVM_BUILD_DOCS=ON
 DOCS_PLIST_FILES=	${MAN1SRCS:S|^|man/man1/|:S|.1$|${LLVM_SUFFIX}.1.gz|}
 EXTRAS_DESC=		Extra clang tools
 EXTRAS_IMPLIES=		CLANG
@@ -143,18 +146,24 @@ LIT_DESC=		Install lit and FileCheck test tools
 LIT_VARS=		_USES_PYTHON=python
 LLD_DESC=		Install lld, the LLVM linker
 LLDB_BUILD_DEPENDS=	swig:devel/swig
-LLDB_CMAKE_ON=		-DLUA_INCLUDE_DIR=${LOCALBASE}/include/lua${LUA_VER_STR} \
-			-DLUA_LIBRARY=${LOCALBASE}/lib/liblua-${LUA_VER}.so \
-			-DCURSES_INCLUDE_PATH=/usr/include \
-			-DCURSES_CURSES_LIBRARY=/usr/lib/libcurses.so \
-			-DCURSES_FORM_LIBRARY=/usr/lib/libform.so \
-			-DCURSES_NCURSES_LIBRARY=/usr/lib/libncurses.so \
-			-DPANEL_LIBRARIES=/usr/lib/libpanel.so
+LLDB_CMAKE_ON= \
+	-DLUA_INCLUDE_DIR=${LOCALBASE}/include/lua${LUA_VER_STR} \
+	-DLUA_LIBRARY=${LOCALBASE}/lib/liblua-${LUA_VER}.so \
+	-DCURSES_INCLUDE_PATH=/usr/include \
+	-DCURSES_CURSES_LIBRARY=/usr/lib/libcurses.so \
+	-DCURSES_FORM_LIBRARY=/usr/lib/libform.so \
+	-DCURSES_NCURSES_LIBRARY=/usr/lib/libncurses.so \
+	-DPANEL_LIBRARIES=/usr/lib/libpanel.so
 LLDB_DESC=		Install lldb, the LLVM debugger
 LLDB_IMPLIES=		CLANG
 LLDB_USES=		lua:53 libedit
 LLDB_VARS=		_USES_PYTHON=python
 OPENMP_DESC=		Install libomp, the LLVM OpenMP runtime library
+OPENMP_CMAKE_ON= \
+	-DLIBOMPTARGET_DEP_LIBELF_INCLUDE_DIR="/usr/include/libelf.h" \
+	-DLIBOMPTARGET_DEP_LIBELF_LIBRARIES="/usr/lib/libelf.so" \
+	-DLIBOMPTARGET_DEP_LIBFFI_INCLUDE_DIR="" \
+	-DLIBOMPTARGET_DEP_LIBFFI_LIBRARIES=""
 OPENMP_PORTDOCS=	openmp
 PYCLANG_DESC=		Install python bindings to libclang
 PYCLANG_IMPLIES=	CLANG