[8u76] Request for approval for CR8146566: OpenJDK build can't handle commas in LDFLAGS

[Andrew Hughes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8146566
Webrev: http://cr.openjdk.java.net/~andrew/8u/8146566/webrev.01/

If additional LDFLAGS containing commas are passed to the build e.g.

--with-extra-ldflags="-Wl,--as-needed -Wl,-O1 -Wl,--hash-style=gnu -Wl,--sort-common"

(which are the default flags on Fedora), then the build will fail as the call to
SetupNativeCompilation expands LDFLAGS_JDKLIB early and the commas are interpreted
to denote separate arguments to this macro.

On current 8u, this only affects the demo code (BUILD_DEMO_JVMTI_$1). It did
affect both the demo code and the main JDK build on 9, and I was planning
to submit a similar fix there. However, 8142907 was added which fixed both cases
there, as well as introducing a number of other changes.

For 8u, I'd like to backport the relevant part of 8142907 under this bug, 8146566.
Without this fix, the build fails with the above option. With it,
it successfully completes. 8142907 in full contains other changes, many specific
to Mac OS, which would introduce unnecessary changes into the 8u build.

Ok to push this?
-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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