RFR: 8146132: Excessive output from make test-image

[Erik Joelsson]

Here is my attempt at solving Coleen's logging issue. This patch changes the log level for the "build info" log messages for all native test libs and executables to `LogInfo`. It also adds a new meta log message for each call to SetupTestFilesCompilation, which is kept on LogWarn level, which prints a single line with the number of test files being compiled in this call. For `make test-image`, we have 5 such calls so the output will look like this, which I think is quite reasonable:


Creating 1 test executable file(s) for BUILD_LIBTEST_JTREG_EXECUTABLES
Creating 45 test library file(s) for BUILD_JDK_JTREG_LIBRARIES
Creating 6 test executable file(s) for BUILD_JDK_JTREG_EXECUTABLES
Creating 853 test library file(s) for BUILD_HOTSPOT_JTREG_LIBRARIES
Creating 16 test executable file(s) for BUILD_HOTSPOT_JTREG_EXECUTABLES

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Commit messages:
 - JDK-8146132

Changes: https://git.openjdk.org/jdk/pull/12052/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12052&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8146132
  Stats: 26 lines in 2 files changed: 22 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/12052.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12052/head:pull/12052

PR: https://git.openjdk.org/jdk/pull/12052