Fix asm::delay not clobbering count register

Author: adamgreig

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
+
+- Fix `asm::delay()` to ensure count register is always reloaded
+
 ## [v0.8.0] - 2022-04-20
 
 ### Added

src/asm.rs

@@ -81,7 +81,8 @@ pub unsafe fn delay(cycles: u32) {
             "1:",
             "addi {0}, {0}, -1",
             "bne {0}, zero, 1b",
-            in(reg) real_cyc
+            inout(reg) real_cyc => _,
+            options(nomem, nostack),
             )
         }