Bless coverage.

Author: cjgillot

tests/coverage/closure.cov-map

@@ -31,16 +31,18 @@ Number of file 0 mappings: 24
     = (c0 - c1)
 - Code(Counter(0)) at (prev + 1, 5) to (start + 3, 2)
 
-Function name: closure::main::{closure#0} (unused)
-Raw bytes (24): 0x[01, 01, 00, 04, 00, 28, 05, 02, 14, 00, 02, 15, 02, 0a, 00, 02, 0a, 00, 0b, 00, 01, 09, 01, 06]
+Function name: closure::main::{closure#0}
+Raw bytes (26): 0x[01, 01, 01, 01, 05, 04, 01, 28, 05, 02, 14, 05, 02, 15, 02, 0a, 02, 02, 0a, 00, 0b, 01, 01, 09, 01, 06]
 Number of files: 1
 - file 0 => global file 1
-Number of expressions: 0
+Number of expressions: 1
+- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
 Number of file 0 mappings: 4
-- Code(Zero) at (prev + 40, 5) to (start + 2, 20)
-- Code(Zero) at (prev + 2, 21) to (start + 2, 10)
-- Code(Zero) at (prev + 2, 10) to (start + 0, 11)
-- Code(Zero) at (prev + 1, 9) to (start + 1, 6)
+- Code(Counter(0)) at (prev + 40, 5) to (start + 2, 20)
+- Code(Counter(1)) at (prev + 2, 21) to (start + 2, 10)
+- Code(Expression(0, Sub)) at (prev + 2, 10) to (start + 0, 11)
+    = (c0 - c1)
+- Code(Counter(0)) at (prev + 1, 9) to (start + 1, 6)
 
 Function name: closure::main::{closure#10} (unused)
 Raw bytes (10): 0x[01, 01, 00, 01, 00, 9b, 01, 07, 00, 21]