DRILL-5799: native-client: Support alternative build directories

[xhochy]

No description provided.

[xhochy]

Build failed with unrelated reasons to this PR:

[WARNING] Rule 0: org.apache.maven.plugins.enforcer.RequireFilesSize failed with message:
The file drill-jdbc-all-1.12.0-SNAPSHOT.jar is outside the expected size range.

                  This is likely due to you adding new dependencies to a java-exec and not updating the excludes in this module. This is important as it minimizes the size of the dependency of Drill application users.
/home/travis/build/apache/drill/exec/jdbc-all/target/drill-jdbc-all-1.12.0-SNAPSHOT.jar size (31071836) too large. Max. is 29000000/home/travis/build/apache/drill/exec/jdbc-all/target/drill-jdbc-all-1.12.0-SNAPSHOT.jar

[paul-rogers]

Build issue has been corrected via another PR.

[xhochy]

@paul-rogers Thanks, rebase fixed the build.

[paul-rogers]

@parthchandra or @sohami, can one of you take a quick look at this one since you are familiar with our C builds?

[parthchandra]

+1. Thanks for the fix.