Is FPC a good Pascal target? The group there has made major strides to embrace the ISO 7185 as a dialect. My only issue with them is that they don't use my help much :) ie, I write HUGE amounts of ISO 7185 tests and they appear to not be using much or any of it, and when they do they don't talk to me (ie., give me any feedback whatever).
Well, talk is cheap ;) Actually we are using your tests from time to time, I used them to get FPCs ISO support in a reasonable shape and we would happily add them to our regression tests. Problem is: the license is unclear.
If gpc, or a "gpc like" compiler were written for LLVM (or similar), I would suggest that be done in Pascal itself.
FPC has also the possibility to use LLVM as backend for selected targets. Funnily enough, if one does serious LLVM support, it requires also adaption for each target. And the same as for gcc applies as well: new versions normally break existing frontends. Not to mention that a LLVM based compiler is ten times slower than one with FPCs backend. The generated code is on average around 10 % faster thought.