creating workflow for mirror::String compression

All-ASCII String characters are stored in 8-bit blocks
instead of 16-bit. The compression has not taken place, but all
workflow are in the code already (changing kUseStringCompression in
string.h file to TRUE will enable the feature)

Notes: Feature works on interpreter only without optimizing

Test art: m ART_TEST_INTERPRETER=true ART_TEST_OPTIMIZING=false
          test-art-host

Also tested with String tests from libcore/:
1. libcore.java.lang.StringTest
2. libcore.java.lang.StringBufferTest
3. libcore.java.lang.StringBuilderTest
4. libcore.java.lang.OldStringTest
5. libcore.java.lang.OldStringBufferTest

Memory improvement is 33% (from 6.03% to 4.03%, total String memory
from all apps per total memory of all apps) measured on Angler
with Hprof tools

Bug: 31040547
Change-Id: I9cc92c265ebf1305fc06b5fc33efd83797660cce

1 files changed, 8 insertions, 1 deletions

diff --git a/test/020-string/src/Main.java b/test/020-string/src/Main.java
index 710808255c..ccf94aabcc 100644
--- a/test/020-string/src/Main.java
+++ b/test/020-string/src/Main.java
@@ -45,7 +45,14 @@ public class Main {
         if (testStr.length() != testStr2.length())
             System.out.println("WARNING: stringTest length mismatch");
 
-        System.out.println("Compare result is " + testStr.compareTo(testStr2));
+        int compareResult = testStr.compareTo(testStr2);
+        if (compareResult > 0) {
+          System.out.println("Compare result is greater than zero");
+        } else if (compareResult == 0) {
+          System.out.println("Compare result is equal to zero");
+        } else {
+          System.out.println("Compare result is less than zero");
+        }
 
         // expected: -65302
         String s1 = "\u0c6d\u0cb6\u0d00\u0000\u0080\u0080\u0080\u0000\u0002\u0002\u0002\u0000\u00e9\u00e9\u00e9";