The raster package has a function
rotate for the opposite problem (go from 0 - 360 to -180 - 180), but not for this one. However, you can do it like this:
r <- rasterize(wrld_simpl, raster())
Cut in two pieces, change the extent of the western hemisphere, and merge again.
x1 <- crop(r, extent(-180, 0, -90, 90))
x2 <- crop(r, extent(0, 180, -90, 90))
extent(x1) <- c(180, 360, -90, 90)
m <- merge(x1, x2)
This assumes a well behaved global raster with edges at -180, and 180 and the zero meridian being in between two columns.