Turn some inline procs into templates

As much as I believe in the power of optimizing compilers, it turned
out that the use of forced inlining with templates still creates a
significant difference in the release builds of nim-faststreams.

stew/ranges/ptr_arith.nim

@@ -1,12 +1,12 @@
 proc baseAddr*[T](x: openarray[T]): pointer = cast[pointer](x)
 
-proc shift*(p: pointer, delta: int): pointer {.inline.} =
+template shift*(p: pointer, delta: int): pointer =
   cast[pointer](cast[int](p) + delta)
 
-proc distance*(a, b: pointer): int {.inline.} =
+template distance*(a, b: pointer): int =
   cast[int](b) - cast[int](a)
 
-proc shift*[T](p: ptr T, delta: int): ptr T {.inline.} =
+template shift*[T](p: ptr T, delta: int): ptr T =
   cast[ptr T](shift(cast[pointer](p), delta * sizeof(T)))
 
 when (NimMajor,NimMinor,NimPatch) >= (0,19,9):