[8u] RFA: 8036003: Add --with-native-debug-symbols=[none|internal|external|zipped]

[Severin Gehwolf]

Hi,

Please approve this enhancement backport for JDK 8u. It adds a new
configure option:
--with-native-debug-symbols=[none|internal|external|zipped]

Such an option exists in JDK 9+ already and we've been using the --
with-native-debug-symbols=internal switch for our distribution OpenJDK
builds ever since. The backport was done in a way so that old behaviour
keeps working. For example, if the new configure flag is missing this
should be a no-op for existing build configs. However, if the new
option is present, it'll use --with-native-debug-symbols, overriding
old configure flags --disable-debug-symbols and --disable-zip-debug-
info. This enhancement also fixes bug JDK-8207234[1].

bug: https://bugs.openjdk.java.net/browse/JDK-8036003
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8036003/webrev.02/
review-thread: http://mail.openjdk.java.net/pipermail/build-dev/2018-July/022686.html

Thanks,
Severin

[1] https://bugs.openjdk.java.net/browse/JDK-8207234