This saves code space in builds which use link-time optimization.
The optimization drops the untranslated strings and replaces them
with a compressed_string_t struct. It can then be decompressed to
a c string.
Builds without LTO work as well but include both untranslated
strings and compressed strings.
This work could be expanded to include QSTRs and loaded strings if
a compress method is added to C. Its tracked in #531.
Its slimmed down by removing the qstr and bit packing TCC info.
The trinket m0 build actually grows by 20 bytes. The arduino zero
build shrinks by 188 bytes.
1. UART: ported to ASF4. Allow rx-only and tx-only. Add .baudrate r/w property.
2. Make NeoPixel timing deterministic by turning off caches during NeoPixel writes.
3. Incorporate asf4 updates:
a. async USART driver
b. bringing Atmel START configuration closer to what we use
c. Clock initialization order now specified by CIRCUITPY_GCLK_INIT_1ST and _LAST.
4. supervisor/port.c: Move commented-out clock-test pin setting to correct location.
all: Add .frequency read-only property for busio.SPI to return actual frequency.
Fix esp8266/posix_helpers.c, which was not up to date for the new
long-lived/short-lived heap allocation scheme.
Also, fixed pin mappings for rev B Metro M4:
swap PA12 and PA13 on SPI 2x3 header
swap A3 and A5
Comment out all frozen modules in CPX again to make room while waiting
for SPI flash.
Scott Shawcroft
Scott Shawcroft
Bryan Siepert
Dan Halbert