Update Eigen to commit:e16d70bd4e9cdebd2fbdae63b1a4d86493fbbde6

CHANGELOG
=========
e16d70bd4 - Fix FFT when destination does not have unit stride.
99c18bce6 - Msvc muluh
8e4797178 - Bit shifting functions
9700fc847 - Reorganize CMake and minimize configuration for non-top-level builds.

PiperOrigin-RevId: 631975359
Change-Id: I537052ef6b9ed6e3ecf90e2aebf5c3898ffc919c
12 files changed