spirv-tools: remove ports-gcc workaround

tweaked diff from Brad

graphics/spirv-tools/Makefile

@@ -35,16 +35,7 @@ DPB_PROPERTIES =	parallel
 CONFIGURE_ARGS =	-DSPIRV-Headers_SOURCE_DIR="${LOCALBASE}" \
 			-DSPIRV_WERROR=OFF
 
-SUBST_VARS +=	ADDITIONAL_LIBRARIES
-
-pre-configure:
-	${SUBST_CMD} ${WRKSRC}/tools/CMakeLists.txt
-
 # effcee is missing to build tests
 NO_TEST =	Yes
 
 .include <bsd.port.mk>
-
-.if ${CHOSEN_COMPILER} == ports-gcc
-ADDITIONAL_LIBRARIES = stdc++fs
-.endif

graphics/spirv-tools/patches/patch-tools_CMakeLists_txt

@@ -1,14 +0,0 @@
-Add -lstdc++fs for ports-gcc
-
-Index: tools/CMakeLists.txt
---- tools/CMakeLists.txt.orig
-+++ tools/CMakeLists.txt
-@@ -86,7 +86,7 @@ if (NOT ${SPIRV_SKIP_EXECUTABLES})
-                            util/cli_consumer.cpp
-                            io.cpp
-                            ${COMMON_TOOLS_SRCS}
--                      LIBS ${SPIRV_TOOLS_FULL_VISIBILITY})
-+                      LIBS ${SPIRV_TOOLS_FULL_VISIBILITY} ${ADDITIONAL_LIBRARIES})
-     target_include_directories(spirv-objdump PRIVATE ${spirv-tools_SOURCE_DIR}
-                                                      ${SPIRV_HEADER_INCLUDE_DIR})
-     set(SPIRV_INSTALL_TARGETS ${SPIRV_INSTALL_TARGETS} spirv-objdump)