It seems like the sdk_version partially controls which
libc++ is used during compilation. This causes mismatches
when some targets specify a version and some targets do not.

Bug: b/138239233
Bug: b/142276229
Test: built locally
Change-Id: Idd4ede2fd3c162dd0edd850155daff70b2c05bd2
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/37168
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Tested-by: Jason Macnak <natsu@google.com>