Introduce non-DEFAULT OPTION for link-time-optimisation

PR:		242829
Submitted by:	daniel.engberg.lists@pyret.net

multimedia/ffmpeg/Makefile

@@ -39,7 +39,7 @@ OPTIONS_DEFINE=	ALSA AMR_NB AMR_WB AOM ARIBB24 ASS BEIGNET BS2B CACA CDIO CELT \
 		CODEC2 DAV1D DAVS2 DC1394 DEBUG DOCS DRM FDK_AAC FLITE \
 		FONTCONFIG FREETYPE FREI0R FRIBIDI GME GSM ICONV ILBC JACK \
 		KLVANC KVAZAAR LADSPA LAME LENSFUN LIBBLURAY LIBRSVG2 LIBXML2 \
-		LV2 MFX MODPLUG MYSOFA OPENAL OPENCL OPENCV OPENGL OPENH264 \
+		LTO LV2 MFX MODPLUG MYSOFA OPENAL OPENCL OPENCV OPENGL OPENH264 \
 		OPENJPEG OPENMPT OPTIMIZED_CFLAGS OPUS POCKETSPHINX PULSEAUDIO \
 		RAV1E RTCPU RUBBERBAND SDL SMB SNAPPY SNDIO SOXR SPEEX SRT SSH \
 		SVTAV1 SVTHEVC SVTVP9 TENSORFLOW TESSERACT THEORA TWOLAME V4L \
@@ -111,6 +111,7 @@ ILBC_DESC=	Internet Low Bit Rate codec
 KLVANC_DESC=	Kernel Labs VANC processing
 KVAZAAR_DESC=	H.265 video codec support via Kvazaar
 LICENSE_DESC=	Licensing options
+LTO_DESC=	Use Link-Time Optimization
 LV2_DESC=	LV2 audio filtering
 MFX_DESC=	Intel MediaSDK (aka Quick Sync Video)
 MYSOFA_DESC=	SOFAlizer binaural filter
@@ -316,6 +317,9 @@ LIBRSVG2_CONFIGURE_ENABLE=	librsvg
 LIBXML2_LIB_DEPENDS=	libxml2.so:textproc/libxml2
 LIBXML2_CONFIGURE_ENABLE=	libxml2
 
+# lto
+LTO_CONFIGURE_ENABLE=	lto
+
 # lv2
 LV2_BUILD_DEPENDS=	lv2>0:audio/lv2
 LV2_LIB_DEPENDS=	liblilv-0.so:audio/lilv