Bless coverage.

Author: cjgillot

tests/coverage-map/status-quo/async2.cov-map

@@ -7,19 +7,17 @@ Number of file 0 mappings: 1
 - Code(Counter(0)) at (prev + 11, 1) to (start + 0, 23)
 
 Function name: async2::async_func::{closure#0}
-Raw bytes (28): 0x[01, 01, 02, 01, 05, 05, 02, 04, 01, 0b, 17, 03, 09, 05, 03, 0a, 02, 06, 02, 02, 06, 00, 07, 07, 01, 01, 00, 02]
+Raw bytes (26): 0x[01, 01, 01, 05, 00, 04, 01, 0b, 17, 03, 09, 05, 03, 0a, 02, 06, 00, 02, 06, 00, 07, 03, 01, 01, 00, 02]
 Number of files: 1
 - file 0 => global file 1
-Number of expressions: 2
-- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
-- expression 1 operands: lhs = Counter(1), rhs = Expression(0, Sub)
+Number of expressions: 1
+- expression 0 operands: lhs = Counter(1), rhs = Zero
 Number of file 0 mappings: 4
 - Code(Counter(0)) at (prev + 11, 23) to (start + 3, 9)
 - Code(Counter(1)) at (prev + 3, 10) to (start + 2, 6)
-- Code(Expression(0, Sub)) at (prev + 2, 6) to (start + 0, 7)
-    = (c0 - c1)
-- Code(Expression(1, Add)) at (prev + 1, 1) to (start + 0, 2)
-    = (c1 + (c0 - c1))
+- Code(Zero) at (prev + 2, 6) to (start + 0, 7)
+- Code(Expression(0, Add)) at (prev + 1, 1) to (start + 0, 2)
+    = (c1 + Zero)
 
 Function name: async2::async_func_just_println
 Raw bytes (9): 0x[01, 01, 00, 01, 01, 13, 01, 00, 24]