Implement regularizations for Euler eq

Implements the Navier-Stokes and general regularization from J.-L. Guermond and B. Popov, “Viscous regularization of the euler equations and entropy principles,” SIAM Journal on Applied Mathematics, vol. 74, no. 2, pp. 284–305, 2014.

src/HRSC/bernstein.jl

@@ -60,7 +60,7 @@ Compute inplace a convex combination of `u!` and its Bernstein reconstruction we
 grid to the bernstein grid and back, respectively.
 `m` and `M` keywords allow to enforce lower and upper bound in reconstruction.
 """
-function reconstruct_cell!(u, w, P, V; m=missing, M=missing)
+@inline function reconstruct_cell!(u, w, P, V; m=missing, M=missing)
 
   uB = P * u