RFR: JDK-8315278: Patch 'print-targets' target to print targets separated by new line [v2]

[Cesar Soares Lucas]

> Currently 'make print-targets' print all targets on the same line separated by space. That isn't only terribly to read but hard to "grep". Printing each target on a separate line seems much better.
> 
> Tested on: Linux x64, Windows x64 and MacOS AArch64

Cesar Soares Lucas has updated the pull request incrementally with one additional commit since the last revision:

  Update make/Main.gmk
  
  Patching the target to instead use internal make functions as suggested by erikj79.
  
  Co-authored-by: Erik Joelsson <37597443+erikj79 at users.noreply.github.com>

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15479/files
  - new: https://git.openjdk.org/jdk/pull/15479/files/629ec9f2..9b22bb6c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15479&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15479&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15479.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15479/head:pull/15479

PR: https://git.openjdk.org/jdk/pull/15479