- Add `-Wl,--gc-sections` to LDFLAGS
- Add `-fdata-sections` and `-ffunction-sections` to CFLAGS
- Update lpc2387 linker script to keep the isr vector and init
sections when garbage collecting.
- Keep .ctors and .dtors sections (similar to what binutils default
linker script does when building for Linux targets)
Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>