Release 1.2.2

Changes since 1.2.1:

Fix the placement of comments in the instrumented code, except for some
edge cases in expression switch statements and type switch statements.

Fix instrumentation of parenthesized nil, struct types and interface
types in type switch statements.

Fix instrumentation of black box tests (those with 'package X_test').

In the instrumented conditions for expression switch statements and type
switch statements, omit parentheses where possible.

Generate simpler code when instrumenting expression switch statements.

main.go

@@ -13,7 +13,7 @@ import (
 	"strings"
 )
 
-const version = "1.2.2-snapshot"
+const version = "1.2.2"
 
 var exit = os.Exit