Add code size optimization flags.

embassy-nrf-examples/.cargo/config

@@ -1,3 +1,8 @@
+[unstable]
+namespaced-features = true
+build-std = ["core"]
+build-std-features = ["panic_immediate_abort"]
+
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 runner = "probe-run --chip nRF52840_xxAA"
 
@@ -7,17 +12,12 @@ rustflags = [
   "-C", "link-arg=-Tlink.x",
   "-C", "link-arg=-Tdefmt.x",
 
-  # if you run into problems with LLD switch to the GNU linker by commenting out
-  # this line
-  # "-C", "linker=arm-none-eabi-ld",
-
-  # if you need to link to pre-compiled C libraries provided by a C toolchain
-  # use GCC as the linker by commenting out both lines above and then
-  # uncommenting the three lines below
-  # "-C", "linker=arm-none-eabi-gcc",
-  # "-C", "link-arg=-Wl,-Tlink.x",
-  # "-C", "link-arg=-nostartfiles",
+  # Code-size optimizations.
+  "-Z", "trap-unreachable=no",
+  "-C", "inline-threshold=5",
+  "-C", "no-vectorize-loops",
 ]
 
 [build]
 target = "thumbv7em-none-eabi"
+