Fix large integer literals in dart2js_extra/round_constant_folding_test

Change-Id: Idf09515e7d31c1e778c8fa99c94d40e9939d286f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107831
Reviewed-by: Stephen Adams <sra@google.com>
Commit-Queue: Stephen Adams <sra@google.com>

Author: rakudrama

tests/compiler/dart2js_extra/round_constant_folding_test.dart

@@ -53,8 +53,9 @@ const int PI2 = 1;
 const int PI3 = 0x1234;
 const int PI4 = 0x12345678;
 const int PI5 = 0x123456789AB;
-const int PI6 = 0x123456789ABCDEF;
-const int PI7 = 0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF;
+const int PI6 = 0x123456789ABCD00 + 0xEF;
+const int PI7 = 0x123456789ABCD * 0x1234567 * 0x1234567 * 0x1234567;
+//const int PI7 = 0x123456789ABCDEF0123456789ABCDEF0123456789ABCDEF;
 
 const int NI1 = 0 - PI1;
 const int NI2 = -PI2;