Add rpath for libc++ libraries in order to not specify rpath by user each time. Disable -frthlib-add-ppath by default for VE similar to other architectures. Update regression tests to check modifications.
Add rpath for libc++ libraries in order to not specify rpath by user each time. Disable -frthlib-add-ppath by default for VE similar to other architectures. Update regression tests to check modifications.