Auto merge of #143 - jonas-schievink:armv6default, r=jonas-schievink

Assume ARMv6 when `<cpu>` section is missing

This makes the generated crates build in more cases.

Author: homunkulus

Cargo.lock

@@ -242,8 +242,8 @@ pub fn interrupt(
     match *target {
         Target::CortexM => {
             let is_armv6 = match device.cpu {
-                Some(ref cpu) if cpu.name.starts_with("CM0") => true,
-                _ => false,
+                Some(ref cpu) => cpu.name.starts_with("CM0"),
+                None => true,  // default to armv6 when the <cpu> section is missing
             };
 
             if is_armv6 {