Fix getuniname for control's. Fixes RT122470 RT122471

Also adds tests for the lowest and highest codepoint for each of the
ranges of control codepoints, as well as one above and below these
to ensure the range is correct.

src/vm/jvm/runtime/org/perl6/nqp/runtime/Ops.java

@@ -7173,7 +7173,12 @@ public static String getuniname(long codePoint, ThreadContext tc) {
         try {
             if(codePoint < 0) {
                 name = "<illegal>";
-            } else {
+            }
+            /* Return <control-XXXX> for control characters */
+            else if (codePoint <= 0x1F || (0x7F <= codePoint && codePoint <= 0x9F)) {
+                name = String.format("<control-%04X>", codePoint);
+            }
+            else {
                 name = Character.getName(cp);
                 if(name == null) {
                     name = "<unassigned>";

t/nqp/106-unicodenames.t

@@ -1,4 +1,4 @@
-plan(19);
+plan(26);
 is(nqp::getstrfromname('FULL STOP'), '.', 'getstrfromname works');
 is(nqp::codepointfromname('FULL STOP'), nqp::ord('.'), 'codepointfromname works');
 is(nqp::getstrfromname('super fake not real name'), '', 'getstrfromname returns empty string for nonexistant codepoint names');
@@ -55,3 +55,10 @@ else {
 is(nqp::codepointfromname('LATIN SMALL LETTER E WITH OGONEK AND TILDE'), -1, 'nqp::codepointfromname doesn\'t accept sequences');
 
 is(nqp::getuniname(104), 'LATIN SMALL LETTER H', 'nqp::getuniname');
+is(nqp::getuniname(0x0), '<control-0000>', 'nqp::getuniname for controls');
+is(nqp::getuniname(0x1F), '<control-001F>', 'nqp::getuniname for controls');
+is(nqp::getuniname(0x20), 'SPACE', 'nqp::getuniname for SPACE');
+is(nqp::getuniname(0x7E), 'TILDE', 'nqp::getuniname for TILDE');
+is(nqp::getuniname(0x7F), '<control-007F>', 'nqp::getuniname for controls');
+is(nqp::getuniname(0x9F), '<control-009F>', 'nqp::getuniname for controls');
+is(nqp::getuniname(0xA0), 'NO-BREAK SPACE', 'nqp::getuniname for controls');