Do not use mincore() on Fuchsia.

Fuchsia does not have disk-backed swap space, so a mincore()
implementation does not make sense. Always return true in loaded0,
indicating a hint that the pages parameterized are in memory.

Bug: 119271070
Bug: 119503290
Test: Compile walleye on aosp.
Change-Id: I857557651ada4e88806f20a3ba84843e5590b23b
1 file changed