I suspect that supply outstrips demand in academia as it does in pretty much every doctoral field. In industry there are people who work on compilers at many companies. In terms of new programming languages, there is and there isn't. There is lots of normal line of business work that benefits or would benefit from domain specific languages. On the other hand, Google's got Brian Kernighan if they need a new major language.
An interest in compilers would be valuable for sustaining a person over the span of years it takes to earn a Phd. On the other hand, I don't know would and wouldn't be considered 'a compiler job' by you and who knows what the 'compiler job' market will be in a few years and how it will relate to what tiny piece of compilers you might work on while pursuing the degree.
Anyway, where you go to school and who your advisor is will also affect how relevant your study is to company's that hire people for 'compiler jobs.'
Good luck.