[regexp] Create property on result for each named capture

test/mjsunit/harmony/regexp-named-captures.js

Index: test/mjsunit/harmony/regexp-named-captures.js
diff --git a/test/mjsunit/harmony/regexp-named-captures.js b/test/mjsunit/harmony/regexp-named-captures.js
index ced8e4b2f6ba330698f43bbcad1a5a7afc72c82c..53f4e0e7c9c23584500e362f8d32175072a36852 100644
--- a/test/mjsunit/harmony/regexp-named-captures.js
+++ b/test/mjsunit/harmony/regexp-named-captures.js
@@ -74,3 +74,31 @@ assertEquals(["bab", "b"], "bab".match(/(?<a>\k<a>\w)../u));
 // Reference before group.
 assertEquals(["bab", "b"], "bab".match(/\k<a>(?<a>b)\w\k<a>/u));
 assertEquals(["bab", "b", "a"], "bab".match(/(?<b>b)\k<a>(?<a>a)\k<b>/u));
+
+// Reference properties.
+assertEquals("a", /(?<a>a)(?<b>b)\k<a>/u.exec("aba").a);
+assertEquals("b", /(?<a>a)(?<b>b)\k<a>/u.exec("aba").b);
+assertEquals(undefined, /(?<a>a)(?<b>b)\k<a>/u.exec("aba").c);
+assertFalse(/(?<a>a)(?<b>b)\k<a>/u.exec("aba").hasOwnProperty("c"));
+assertEquals(undefined, /(?<a>a)(?<b>b)\k<a>|(?<c>c)/u.exec("aba").c);
+assertTrue(/(?<a>a)(?<b>b)\k<a>|(?<c>c)/u.exec("aba").hasOwnProperty("c"));
+
+// Unicode names.
+assertEquals("a", /(?<π>a)/u.exec("bab").π);
+assertEquals("a", /(?<\u{03C0}>a)/u.exec("bab").\u03C0);
+assertEquals("a", /(?<$>a)/u.exec("bab").$);
+assertEquals("a", /(?<_>a)/u.exec("bab")._);
+assertEquals("a", /(?<$𐒤>a)/u.exec("bab").$𐒤);
+assertEquals("a", /(?<_\u200C>a)/u.exec("bab")._\u200C);
+assertEquals("a", /(?<_\u200D>a)/u.exec("bab")._\u200D);
+assertEquals("a", /(?<ಠ_ಠ>a)/u.exec("bab").ಠ_ಠ);
+assertThrows('/(?<❤>a)/u');
+assertThrows('/(?<𐒤>a)/u');  // ID_Continue but not ID_Start.
+
+// Capture name conflicts.
+assertThrows(() => /(?<index>a)/u);
+assertThrows(() => /(?<input>a)/u);
+assertThrows(() => /(?<length>a)/u);
+
+assertEquals("a", /(?<inde>a)/u.exec("a").inde);
+assertEquals("a", /(?<indexi>a)/u.exec("a").indexi);