Add tests for dassert with 'in'

Author: wilzbach

src/core/internal/dassert.d

@@ -41,7 +41,11 @@ auto miniFormat(V)(auto ref V v)
 {
     import core.stdc.stdio : sprintf;
     import core.stdc.string : strlen;
-    static if (__traits(isIntegral, V))
+    static if (is(V : bool))
+    {
+        return v ? "true" : "false";
+    }
+    else static if (__traits(isIntegral, V))
     {
         enum printfFormat = getPrintfFormat!V;
         char[20] val;

test/exceptions/src/assert_fail.d

@@ -108,6 +108,8 @@ void testStruct()()
 void testAA()()
 {
     test([1:"one"], [2: "two"], `[1: "one"] != [2: "two"]`);
+    test!"in"(1, [2: 3], "1 !in [2: 3]");
+    test!"in"("foo", ["bar": true], `"foo" !in ["bar": true]`);
 }
 
 void main()