This property specifies the flag used to pass the linker script filename
through the compiler front end tot he linker.
For clang, we use the general purpose linker-pass through -Wl flag with -T:
-Wl,-T as clang doesn't support -T.
For gcc, we use -T directly as this keeps the picolibc specs file from
inserting the picolibc linker script as well.
If the compiler doesn't specify a value, we continue to use -Wl,-T as
before.
Signed-off-by: Keith Packard <keithp@keithp.com>
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