openjdk9: init at 9.0.0+180

* openjdk 8: code cleanup

as recommended by 0xABAB in #27194

* openjdk 9: init at ea build 176

this starts with copy of 8.nix and just updates hashes and replaces 8
with 9.  it also tweaks the version handling because we aren't dealing
with an update version yet.

* openjdk 9: adapt patches from openjdk 8

fix-java-home: surrounding code changed slightly

swing-use-gtk-jdk9: location of the file being patched changed due to
modularization

read-truststore-from-env: the code that handles the trustStore was
refactored out into a helper class in upstream commit
http://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/904861872c0e

adlc_updater: this isn't present anymore

* openjdk 9: make two more warnings-as-errors non-fatal

this requires that we switch to configureFlagsArray to deal with
whitespace

the errors being suppressed are show below:

* For target support_native_java.desktop_libawt_xawt_awt_Robot.o:
/tmp/nix-build-openjdk-9ea-b176.drv-0/jdk9-jdk-9+176/jdk/src/java.desktop/unix/native/libawt_xawt/awt/awt_Robot.c: In function 'isXCompositeDisplay':
/tmp/nix-build-openjdk-9ea-b176.drv-0/jdk9-jdk-9+176/jdk/src/java.desktop/unix/native/libawt_xawt/awt/awt_Robot.c:152:50: error: embedded '\0' in format
[-Werror=format-contains-nul]
     snprintf(NET_WM_CM_Sn, sizeof(NET_WM_CM_Sn), "_NET_WM_CM_S%d\0", screenNumber);
                                                  ^
/tmp/nix-build-openjdk-9ea-b176.drv-0/jdk9-jdk-9+176/jdk/src/java.desktop/unix/native/libawt_xawt/awt/awt_Robot.c:152:50: error: embedded '\0' in format
[-Werror=format-contains-nul]
cc1: all warnings being treated as errors
* For target support_native_jdk.hotspot.agent_libsa_ps_core.o:
/tmp/nix-build-openjdk-9ea-b176.drv-0/jdk9-jdk-9+176/hotspot/src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c: In function 'read_exec_segments':
/tmp/nix-build-openjdk-9ea-b176.drv-0/jdk9-jdk-9+176/hotspot/src/jdk.hotspot.agent/linux/native/libsaproc/ps_core.c:834:7: error: ignoring return value of 'pread', declared
with attribute warn_unused_result [-Werror=unused-result]
       pread(ph->core->exec_fd, interp_name, exec_php->p_filesz, exec_php->p_offset);
       ^
cc1: all warnings being treated as errors

* openjdk 9: ea+176 -> ea+180

* openjdk 9: TODO disable infinality patches, at least to start

the code being patched here seems to have changed substantially or
perhaps even disappeared altogether.  need to investigate whether
these patches are still relevant.

* openjdk 9: update installPhase for modularization

* separate jdk and jre images are now present under build/*/images

* samples have been removed (JEP 298)
  -- TODO that JEP says demos will be gone too, but it seems some are still present?

* bina directory is no longer present

* openjdk 9: TODO handle *.pf files or purge this code completely

* openjdk 9: update minimal jre components

in particular, the name of the config option for headless has changed,
per https://bugs.openjdk.java.net/browse/JDK-8163102

* TODO about echo -n vs printWords, #27427