RFR: 8370503: Use String.newStringWithLatin1Bytes to simplify Integer/Long toString method

[Shaojin Wen]

With the introduction of String.newStringWithLatin1Bytes, we can use it to simplify the toString methods of Integer and Long. By replacing the implementation that supports COMPACT_STRING = false with newStringWithLatin1Bytes, we gain the following benefits:
1. Simplified implementation
2. Strings with codeSize < 35 in Integer.toString(int) and Long.toString(long) can be inlined in C1, improving performance in early calls.

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Commit messages:
 - Simplify toString() implementations in Integer and Long classes\n\nReplace conditional COMPACT_STRINGS checks with direct calls to\nString.newStringWithLatin1Bytes() for better code clarity and\nmaintainability. This change affects:\n\n- Integer.toString(int)\n- Integer.toUnsignedString0(int, int)\n- Long.toString(long)\n- Long.toUnsignedString0(long, int)\n\nThe new approach leverages the existing String.newStringWithLatin1Bytes()\nmethod which already handles the COMPACT_STRINGS logic internally.

Changes: https://git.openjdk.org/jdk/pull/27929/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27929&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8370503
  Stats: 36 lines in 2 files changed: 0 ins; 24 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/27929.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27929/head:pull/27929

PR: https://git.openjdk.org/jdk/pull/27929