Since JDK-8217728, where I introduced some optimizations for handling of the generated make dependency files for native compilation, building hotspot incrementally on Solaris has been broken. The reason for the breakage is that there is a clash between the *.d (header) files created by the dtrace build and the *.d (make) files created by the compiler. The optimization was to cat all the *.d make file together into a single file, but if dtrace is enabled, this cat will inadvertently include the dtrace files as well, which causes parse errors in make when make tries to include the resulting file.

I suggest we fix this by using a different file suffix for the dtrace files in the hotspot objs dir.