A recent change caused the openjdk build to unconditionally use libc++ when using clang. Instead, the build should generally let the toolchain decide which standard library to use, e.g. defaulting always to libstdc++ on Linux. Especially since the presence of libc++ is never tested for.

=== Output from failing command(s) repeated here ===
* For target hotspot_variant-server_libjvm_gtest_objs_BUILD_GTEST_LIBJVM_link:
/usr/bin/ld: cannot find -lc++
clang: error: linker command failed with exit code 1 (use -v to see invocation)
* For target hotspot_variant-server_libjvm_objs_BUILD_LIBJVM_link:
/usr/bin/ld: cannot find -lc++
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Introduced by:

changeset: 49523:69c6eb97297f
user: erikj
date: 2018-04-04 16:13 -0700
8196724: Change macosx deployment target to 10.9
Reviewed-by: tbell, gziemski