I am having trouble finding explicit evidence on any FPGA vendors website that their chip supports the verilog-ams and/or verilog-a. Do all these chips support it, or is it only "mixed-signal" chips, or something different entirely.
I know of no significant FPGA manufacturer that supports analog-anything, so I don't see why they would support Verilog-AMS or Verilog-A.
For the record (because someone will try to point this out as a "flaw" in my logic): PLL's, ADC's, DAC's, and high speed transceivers are NOT analog circuits in this context. Although modern FPGA's have these blocks in them, the analog parts are not re-configurable and the analog stuff is not exposed to the Verilog/VHDL programmer.
Every couple of years some new FPGA maker pops up claiming to have "Analog FPGA's" or some similar buzzword. Most of the time it's the same FPGA as before, just bought by a new company. I've looked into it in the past and the analog performance wasn't great (signal to noise, dynamic range, frequency response, etc). Usually these "new" FPGA companies never go into production and soon close their doors. I can't remember what the names of any of these companies are, and a quick Google search shows no manufacturers doing anything in the past year.
The closest to an "Analog FPGA" that I know of today is the Cypress Semiconductor PSoC stuff. Although you have to use their graphical user interface to configure the analog blocks and can't use anything like a "language".