RFR: 8146132: Excessive output from make test-image [v2]

[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

Erik Joelsson has updated the pull request incrementally with one additional commit since the last revision:

  Fix formatting

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12052/files
  - new: https://git.openjdk.org/jdk/pull/12052/files/f388ecc9..513d5368

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12052&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12052&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 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