[11u] RFR 8224202: Speed up Properties.load

[Aleksey Shipilev]

Original RFE:
  https://bugs.openjdk.java.net/browse/JDK-8224202
  http://hg.openjdk.java.net/jdk/jdk/rev/cdb107ca16e6

Patch applies cleanly to 11u, but does not compile, because there is no ArraysSupport.newLength
(introduced in 13 with JDK-8223593). So, I had to rewrite that block with:

diff -r 436f75b57855 src/java.base/share/classes/java/util/Properties.java
--- a/src/java.base/share/classes/java/util/Properties.java     Thu May 23 18:43:47 2019 +0200
+++ b/src/java.base/share/classes/java/util/Properties.java     Wed Aug 07 16:09:07 2019 +0200
@@ -49,5 +49,4 @@
 import jdk.internal.misc.SharedSecrets;
 import jdk.internal.misc.Unsafe;
-import jdk.internal.util.ArraysSupport;
 import jdk.internal.util.xml.PropertiesDefaultHandler;

@@ -568,5 +567,13 @@
                     lineBuf[len++] = c;
                     if (len == lineBuf.length) {
-                        lineBuf = new char[ArraysSupport.newLength(len, 1, len)];
+                        int maxLen = Integer.MAX_VALUE - 8; // VM allocation limit
+                        int newLen = len*2;
+                        if (newLen < 0) { // overflow?
+                            newLen = maxLen;
+                        }
+                        if (newLen > maxLen) { // over VM limit?
+                            newLen = maxLen;
+                        }
+                        lineBuf = new char[newLen];
                         System.arraycopy(this.lineBuf, 0, lineBuf, 0, len);
                         this.lineBuf = lineBuf;

It is similar to what we had before, but with VM allocation limit treatment that
ArraysSupport.newLength would give us.

Full 11u webrev:
  http://cr.openjdk.java.net/~shade/8224202/webrev.11u.01/

Testing: tier1

-- 
Thanks,
-Aleksey