Cherry-pick 7.11 changes to 8.3

Cherry-picked commits:
c64829b2: Fallback to open if multifs_open fails.
21770732: Fix gdbserver process interruption.
35ee6839: Remove gdb hack.
78af0f6f: Handle cross compile for locale configuration
5cbd102d: Specify osabi in arm/aarch64 tdescs.
dfc5ca4a: Set the default gdb osabi to GNU/Linux.

Bug: 62547070
Test: build
Change-Id: I00a97aa866255ed853c13b8f11dc1a996ea810f2