[toolchain] Enable LLD, LTO and minsize by default #6455

Job	Run time
Lint (quick)	3m 32s
Build documentation	5m 15s
Lint (slow)	11m 7s
Airgapped build	11m 4s
CW305's Bitstream	2m 58s
Run OTBN crypto tests	2m 52s
Run OTBN smoke Test	2m 54s
Verible lint	1m 45s
Verilated Earl Grey	57m 50s
Verilated English Breakfast	3m 49s
Build Docker Containers	2m 25s
Build and test Darjeeling software	3m 59s
QEMU smoketest	2m 26s
Build and test software	19m 23s
Earl Grey for CW310 / Build bitstream	1h 3m 8s
Earl Grey for CW310 Hyperdebug / Build bitstream	1h 4m 55s
Earl Grey for CW340 / Build bitstream	1h 29m 14s
CW310 Test ROM Tests / FPGA test	3m 32s
CW310 ROM Tests / FPGA test	36m 37s
CW310 Manufacturing Tests / FPGA test	27m 54s
CW310 SiVal Tests / FPGA test	25m 40s
Hyper310 ROM_EXT Tests / FPGA test	2m 14s
CW310 SiVal ROM_EXT Tests / FPGA test	27m 23s
Cache bitstreams to GCP	0s
CW340 ROM_EXT Tests / FPGA test	4m 44s
CW340 ROM Tests / FPGA test	45s
CW340 Test ROM Tests / FPGA test	3m 27s
CW340 Manufacturing Tests / FPGA test	2m 21s
CW340 SiVal Tests / FPGA test	14m 24s
CW340 SiVal ROM_EXT Tests / FPGA test	4m 2s
Verify FPGA jobs	23s
	8h 22m 2s

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