DMD release compiler flags when building with LDC

[kinke]

On Tuesday, 22 October 2019 at 14:02:28 UTC, Per Nordlöw wrote:
>     ENABLE_LTO=1 \

This has exactly 0 effect on DMD itself, from DMD's src/posix.mak:

ifdef ENABLE_LTO
CXXFLAGS  += -flto
endif