RFR: 8343074: test/jdk/com/sun/net/httpserver/docs/test1/largefile.txt could be generated [v3]

[Volkan Yazici]

> Adds `test.lib.Utils::createTempFileOfSize` to generate `test/jdk/com/sun/net/httpserver/docs` contents at runtime. This directory contains `largefile.txt` of size 2.6MiB showing up as the 4th largest file tracked by git:
> 
> 
> $ git ls-files | while read f; do echo -e $(stat -c %s "$f")"\t$f"; done >/tmp/trackedFileSizes.txt
> $ sort -n /tmp/trackedFileSizes.txt | tail -n 4
> 2730088	test/jdk/com/sun/net/httpserver/docs/test1/largefile.txt
> 2798680	src/java.base/share/data/unicodedata/NormalizationTest.txt
> 3574947	test/jdk/java/foreign/libTestDowncallStack.c
> 7128495	test/jdk/java/foreign/libTestUpcallStack.c
> 
> 
> **Other highlights:**
> 
> - `jdk.httpclient.test.lib.common.TestUtil` is removed in favor of similar alternatives in `test.lib.Utils` and `test.lib.Asserts`
> - `test.lib.Asserts::assertFileContentsEqual` is added

Volkan Yazici has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains nine additional commits since the last revision:

 - Replace forgotten `assertFileContentsEqual()` calls
 - Merge remote-tracking branch 'upstream/master' into LargeFile
 - Remove `assertFileContentsEqual()`
 - Move file content assertion to `test/lib/Asserts`
 - Move HTTP-specific temp. file methods to `test.lib.Utils`
 - Replace the `docs/test1` folder with dynamically created files
 - Employ `TestUtil::assertFilesEqual` in `sun.net.httpserver` tests
 - Improve `TestUtil::getAFile`
 - Improve `TestUtil::compareFiles`

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/23401/files
  - new: https://git.openjdk.org/jdk/pull/23401/files/421d19d4..a7c44540

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23401&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23401&range=01-02

  Stats: 8138 lines in 188 files changed: 1548 ins; 4470 del; 2120 mod
  Patch: https://git.openjdk.org/jdk/pull/23401.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23401/head:pull/23401

PR: https://git.openjdk.org/jdk/pull/23401