RFR: 8323675: Race in jdk.javadoc-gendata [v2]

[Magnus Ihse Bursie]

> In [JDK-8318913](https://bugs.openjdk.org/browse/JDK-8318913), the symbolgenerator started to look at current sources as well. This means that the gensrc stage needs to be completed before this is run. A dependency was added for jdk.compiler-gendata, but unfortunately the same tool is run also in jdk.javadoc-gendata, where no such safeguard was created.
> 
> The result is that the build can fail intermittently with:
> 
> .../module-info.java:77: error: module not found on module source path
> module java.base {
> ^
> error: cannot access module-info
>   cannot resolve modules
> Exception in thread "main" java.lang.AssertionError
> at jdk.compiler.interim/com.sun.tools.javac.util.Assert.error(Assert.java:155)
> at jdk.compiler.interim/com.sun.tools.javac.util.Assert.checkNonNull(Assert.java:62)
> at jdk.compiler.interim/com.sun.tools.javac.comp.Modules.allModules(Modules.java:1225)
> at jdk.compiler.interim/com.sun.tools.javac.comp.Modules.getObservableModule(Modules.java:1450)
> at jdk.compiler.interim/com.sun.tools.javac.model.JavacElements.getModuleElement(JavacElements.java:144)
> at jdk.compiler.interim/com.sun.tools.javac.model.JavacElements.getModuleElement(JavacElements.java:89)
> at build.tools.symbolgenerator.JavadocElementList.main(JavadocElementList.java:98)
> Compiling up to 2 files for BUILD_BREAKITERATOR_BASE
> Compiling up to 2 files for BUILD_BREAKITERATOR_LD
> make[3]: *** [.../_element_lists.marker] Error 1
> Gendata.gmk:74: recipe for target '.../_element_lists.marker' failed

Magnus Ihse Bursie has updated the pull request incrementally with one additional commit since the last revision:

  Let jdk.javadoc-gendata only depend on GENSRC_TARGETS

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17402/files
  - new: https://git.openjdk.org/jdk/pull/17402/files/fececce6..b679b190

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17402&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17402&range=00-01

  Stats: 9 lines in 1 file changed: 4 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/17402.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17402/head:pull/17402

PR: https://git.openjdk.org/jdk/pull/17402