[numeric separator] Add tests for parseInt

Bug: v8:7317
Change-Id: I6c88de63c4bdb31f873c18c450d26f60659171f2
Reviewed-on: https://chromium-review.googlesource.com/968621
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52030}

test/mjsunit/harmony/numeric-separator.js

@@ -79,6 +79,24 @@
   assertEquals(NaN, dot3);
 }
 
+{
+  assertEquals(1, parseInt('1_2_3'));
+  assertEquals(0, parseInt('0_1_0_1_0'));
+  assertEquals(15, parseInt('0xF_F'));
+  assertEquals(10, parseInt('10e+1_0'));
+  assertEquals(0, parseInt('0o7_7_7'));
+  assertEquals(0, parseInt('0b1_0_1_0'));
+  assertEquals(9, parseInt('9_1.1_3'));
+  assertEquals(1, parseInt('1.1_3'));
+  assertEquals(1, parseInt('1_1.21'));
+  assertEquals(17, parseInt('017_123'));
+
+  assertEquals(1, parseInt('1_2_3', 10));
+  assertEquals(15, parseInt('0xF_F', 16));
+  assertEquals(7, parseInt('7_7_7', 8));
+  assertEquals(1, parseInt('1_0_1_0', 2));
+}
+
 assertThrows('1_0_0_0_', SyntaxError);
 assertThrows('1e_1', SyntaxError);
 assertThrows('1e+_1', SyntaxError);