Don't accidentally skip over pointers in count_const_size

Since we can inline pointer-containing structs into other structs now,
an `isptr` check is insufficient to determine whether or not we need
to recurse here. Also check the actual type of the field in addition.

(cherry picked from commit 793f875)

base/compiler/utilities.jl

@@ -72,18 +72,21 @@ function quoted(@nospecialize(x))
  return is_self_quoting(x) ? x : QuoteNode(x)
 end
 
-function count_const_size(@nospecialize(x))
+function count_const_size(@nospecialize(x), count_self::Bool = true)
  (x isa Type || x isa Symbol) && return 0
  ismutable(x) && return MAX_INLINE_CONST_SIZE + 1
  isbits(x) && return Core.sizeof(x)
  dt = typeof(x)
- sz = sizeof(dt)
+ sz = count_self ? sizeof(dt) : 0
  sz > MAX_INLINE_CONST_SIZE && return MAX_INLINE_CONST_SIZE + 1
  dtfd = DataTypeFieldDesc(dt)
  for i = 1:nfields(x)
- dtfd[i].isptr || continue
  isdefined(x, i) || continue
- sz += count_const_size(getfield(x, i))
+ f = getfield(x, i)
+ if !dtfd[i].isptr && datatype_pointerfree(typeof(f))
+ continue
+ end
+ sz += count_const_size(f, dtfd[i].isptr)
  sz > MAX_INLINE_CONST_SIZE && return MAX_INLINE_CONST_SIZE + 1
  end
  return sz

test/compiler/inline.jl

@@ -330,3 +330,4 @@ struct NonIsBitsDimsUndef
  NonIsBitsDimsUndef() = new()
 end
 @test Core.Compiler.is_inlineable_constant(NonIsBitsDimsUndef())
+@test !Core.Compiler.is_inlineable_constant((("a"^1000, "b"^1000), nothing))