Only print a warning if gcov cannot be found, not an error
Only print a warning if gcov cannot be found, not an error

We have some cases where clang is installed, but not gcc, and there is no convenience symlink for gcov to point to the corresponding clang tool. In this case, coverage won't work, but let's not error out. We can't tell here whether coverage is enabled or not.

Fixes #5066.

PiperOrigin-RevId: 194245346

dropbox/bazel,bazelbuild/bazel,twitter-forks/bazel,akira-baruah/bazel,safarmer/bazel,ButterflyNetwork/bazel,dslomov/bazel-windows,bazelbuild/bazel,perezd/bazel,twitter-forks/bazel,dslomov/bazel,davidzchen/bazel,davidzchen/bazel,bazelbuild/bazel,safarmer/bazel,bazelbuild/bazel,ulfjack/bazel,twitter-forks/bazel,bazelbuild/bazel,perezd/bazel,ButterflyNetwork/bazel,dropbox/bazel,meteorcloudy/bazel,ulfjack/bazel,ulfjack/bazel,cushon/bazel,cushon/bazel,perezd/bazel,perezd/bazel,davidzchen/bazel,safarmer/bazel,katre/bazel,akira-baruah/bazel,dslomov/bazel,meteorcloudy/bazel,meteorcloudy/bazel,aehlig/bazel,aehlig/bazel,dslomov/bazel-windows,ulfjack/bazel,ButterflyNetwork/bazel,katre/bazel,dslomov/bazel,katre/bazel,meteorcloudy/bazel,davidzchen/bazel,meteorcloudy/bazel,akira-baruah/bazel,werkt/bazel,akira-baruah/bazel,safarmer/bazel,werkt/bazel,dslomov/bazel,werkt/bazel,aehlig/bazel,dropbox/bazel,cushon/bazel,dslomov/bazel,dropbox/bazel,davidzchen/bazel,dslomov/bazel,ButterflyNetwork/bazel,ulfjack/bazel,dropbox/bazel,twitter-forks/bazel,ulfjack/bazel,ButterflyNetwork/bazel,ulfjack/bazel,cushon/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,aehlig/bazel,akira-baruah/bazel,katre/bazel,perezd/bazel,katre/bazel,werkt/bazel,katre/bazel,perezd/bazel,werkt/bazel,twitter-forks/bazel,dslomov/bazel-windows,davidzchen/bazel,werkt/bazel,bazelbuild/bazel,dropbox/bazel,dslomov/bazel-windows,dslomov/bazel-windows,safarmer/bazel,aehlig/bazel,cushon/bazel,akira-baruah/bazel,aehlig/bazel,twitter-forks/bazel,dslomov/bazel,perezd/bazel,safarmer/bazel,aehlig/bazel,dslomov/bazel-windows,meteorcloudy/bazel,davidzchen/bazel,twitter-forks/bazel,cushon/bazel