Update the test suite to use mod instead of const

Changes MSRV to 1.42, failing tests updated to match 1.42.

ui/single/exception-invalid.rs

@@ -1,7 +1,7 @@
 #![no_main]
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     #[task(binds = NonMaskableInt)]
     fn nmi(_: nmi::Context) {}
-};
+}

ui/single/exception-systick-used.rs

@@ -1,10 +1,10 @@
 #![no_main]
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     #[task(binds = SysTick)]
     fn sys_tick(_: sys_tick::Context) {}
 
     #[task(schedule = [foo])]
     fn foo(_: foo::Context) {}
-};
+}

ui/single/extern-interrupt-not-enough.rs

@@ -1,7 +1,7 @@
 #![no_main]
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     #[task]
     fn a(_: a::Context) {}
-};
+}

ui/single/extern-interrupt-used.rs

@@ -1,11 +1,11 @@
 #![no_main]
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     #[task(binds = UART0)]
     fn a(_: a::Context) {}
 
     extern "C" {
         fn UART0();
     }
-};
+}

ui/single/locals-cfg.rs

@@ -1,7 +1,7 @@
 #![no_main]
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     #[init]
     fn init(_: init::Context) {
         #[cfg(never)]
@@ -47,4 +47,4 @@ const APP: () = {
     extern "C" {
         fn UART1();
     }
-};
+}

ui/single/locals-cfg.stderr

@@ -28,10 +28,10 @@ error[E0425]: cannot find value `FOO` in this scope
 44 |         FOO;
    |         ^^^ not found in this scope
 
-error: duplicate lang item in crate `panic_halt`: `panic_impl`.
-  |
-  = note: first defined in crate `std`.
-
 error: duplicate lang item in crate `panic_semihosting`: `panic_impl`.
   |
-  = note: first defined in crate `panic_halt`.
+  = note: first defined in crate `std` (which `$CRATE` depends on)
+
+error: duplicate lang item in crate `panic_halt`: `panic_impl`.
+  |
+  = note: first defined in crate `panic_semihosting`.

ui/single/resources-cfg.rs

@@ -1,7 +1,7 @@
 #![no_main]
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     struct Resources {
         #[cfg(never)]
         #[init(0)]
@@ -72,4 +72,4 @@ const APP: () = {
         c.resources.s2;
         c.resources.o5;
     }
-};
+}

ui/single/task-priority-too-high.rs

@@ -3,7 +3,7 @@
 use rtic::app;
 
 #[rtic::app(device = lm3s6965)]
-const APP: () = {
+mod APP {
     #[init]
     fn init(_: init::Context) {}
 
@@ -35,4 +35,4 @@ const APP: () = {
     // this value is too high!
     #[task(binds = I2C0, priority = 9)]
     fn i2c0(_: i2c0::Context) {}
-};
+}

ui/single/task-priority-too-high.stderr

@@ -4,7 +4,7 @@ warning: unused import: `rtic::app`
 3 | use rtic::app;
   |     ^^^^^^^^^
   |
-  = note: #[warn(unused_imports)] on by default
+  = note: `#[warn(unused_imports)]` on by default
 
 error[E0080]: evaluation of constant value failed
  --> $DIR/task-priority-too-high.rs:5:1