Add compilation of examples with new features to test suite

diff --git a/Cargo.toml b/Cargo.toml
index 549e72a..5641d3c 100644
--- a/Cargo.toml
+++ b/Cargo.toml

@@ -24,22 +24,27 @@
 
 [[example]]
 name = "alloc_error"
-path = "examples-alloc/alloc_error.rs"
-required-features = ["alloc"]
+path = "examples-features/alloc_error.rs"
+required-features = ["alloc", "custom_alloc_error_handler"]
 
 [[example]]
 name = "ble_scanning"
-path = "examples-alloc/ble_scanning.rs"
+path = "examples-features/ble_scanning.rs"
 required-features = ["alloc"]
 
 [[example]]
 name = "libtock_test"
-path = "examples-alloc/libtock_test.rs"
+path = "examples-features/libtock_test.rs"
 required-features = ["alloc"]
 
 [[example]]
+name = "panic"
+path = "examples-features/panic.rs"
+required-features = ["custom_panic_handler"]
+
+[[example]]
 name = "simple_ble"
-path = "examples-alloc/simple_ble.rs"
+path = "examples-features/simple_ble.rs"
 required-features = ["alloc"]
 
 [profile.dev]

diff --git a/Makefile b/Makefile
index 34d223e..7d87c28 100644
--- a/Makefile
+++ b/Makefile

@@ -42,7 +42,9 @@
 examples:
 	PLATFORM=nrf52 cargo build --release --target=thumbv7em-none-eabi --examples
 	PLATFORM=nrf52 cargo build --release --target=thumbv7em-none-eabi --examples --features=alloc
-	PLATFORM=opentitan cargo build --release --target=riscv32imc-unknown-none-elf --examples
+	PLATFORM=nrf52 cargo build --release --target=thumbv7em-none-eabi --example panic --features=custom_panic_handler,custom_alloc_error_handler
+	PLATFORM=nrf52 cargo build --release --target=thumbv7em-none-eabi --example alloc_error --features=alloc,custom_alloc_error_handler
+	PLATFORM=opentitan cargo build --release --target=riscv32imc-unknown-none-elf --examples # Important: This is testing a platform without atomics support
 	cd core && cargo build --release --target=thumbv7em-none-eabi --examples --features=custom_panic_handler && cd ..
 
 .PHONY: test

diff --git a/examples-alloc/alloc_error.rs b/examples-alloc/alloc_error.rs
deleted file mode 100644
index ec42b5a..0000000
--- a/examples-alloc/alloc_error.rs
+++ /dev/null

@@ -1,16 +0,0 @@
-// Triggers the out-of-memory handler. Should make all LEDs cycle.
-
-#![no_std]
-
-extern crate alloc;
-
-use alloc::vec::Vec;
-use libtock::result::TockResult;
-
-#[libtock::main]
-fn main() -> TockResult<()> {
-    let mut vec = Vec::new();
-    loop {
-        vec.push(0);
-    }
-}

diff --git a/examples-features/alloc_error.rs b/examples-features/alloc_error.rs
new file mode 100644
index 0000000..40ae939
--- /dev/null
+++ b/examples-features/alloc_error.rs

@@ -0,0 +1,31 @@
+// Triggers the out-of-memory handler. Should print an error message.
+
+#![no_std]
+#![feature(alloc_error_handler)]
+
+extern crate alloc;
+
+use alloc::vec::Vec;
+use core::alloc::Layout;
+use core::fmt::Write;
+use libtock::result::TockResult;
+use libtock::syscalls;
+
+#[libtock::main]
+fn main() -> TockResult<()> {
+    let mut vec = Vec::new();
+    loop {
+        vec.push(0);
+    }
+}
+
+#[alloc_error_handler]
+unsafe fn alloc_error_handler(_: Layout) -> ! {
+    if let Ok(drivers) = libtock::retrieve_drivers() {
+        let mut console = drivers.console.create_console();
+        let _ = writeln!(console, "alloc_error_handler called");
+    }
+    loop {
+        syscalls::raw::yieldk();
+    }
+}

diff --git a/examples-alloc/ble_scanning.rs b/examples-features/ble_scanning.rs
similarity index 100%
rename from examples-alloc/ble_scanning.rs
rename to examples-features/ble_scanning.rs


diff --git a/examples-alloc/libtock_test.rs b/examples-features/libtock_test.rs
similarity index 100%
rename from examples-alloc/libtock_test.rs
rename to examples-features/libtock_test.rs


diff --git a/examples-features/panic.rs b/examples-features/panic.rs
new file mode 100644
index 0000000..5a9123a
--- /dev/null
+++ b/examples-features/panic.rs

@@ -0,0 +1,24 @@
+// Triggers the panic handler. Should print an error message.
+
+#![no_std]
+
+use core::fmt::Write;
+use core::panic::PanicInfo;
+use libtock::result::TockResult;
+use libtock::syscalls;
+
+#[libtock::main]
+async fn main() -> TockResult<()> {
+    panic!("Bye world!");
+}
+
+#[panic_handler]
+unsafe fn panic_handler(_info: &PanicInfo) -> ! {
+    if let Ok(drivers) = libtock::retrieve_drivers() {
+        let mut console = drivers.console.create_console();
+        let _ = writeln!(console, "panic_handler called");
+    }
+    loop {
+        syscalls::raw::yieldk();
+    }
+}

diff --git a/examples-alloc/simple_ble.rs b/examples-features/simple_ble.rs
similarity index 100%
rename from examples-alloc/simple_ble.rs
rename to examples-features/simple_ble.rs


diff --git a/examples/panic.rs b/examples/panic.rs
deleted file mode 100644
index 5abc01a..0000000
--- a/examples/panic.rs
+++ /dev/null

@@ -1,10 +0,0 @@
-// Triggers the panic handler. Should make all LEDs flash.
-
-#![no_std]
-
-use libtock::result::TockResult;
-
-#[libtock::main]
-async fn main() -> TockResult<()> {
-    panic!("Bye world!");
-}