hg: jdk/sandbox: A sketch of incremental build improvements allowing to not rebuilt whole modules.

[jan.lahoda at oracle.com]

Changeset: 4b454fa5c057
Author:    jlahoda
Date:      2020-05-06 13:27 +0200
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/4b454fa5c057

A sketch of incremental build improvements allowing to not rebuilt whole modules.
Parts by erikj.

! make/CompileToolsJdk.gmk
! make/common/JavaCompilation.gmk
! make/jdk/src/classes/build/tools/depend/Depend.java
! src/java.compiler/share/classes/javax/tools/ToolProvider.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/main/JavaCompiler.java