hyperfile: back native mmap with a QEMU aperture

[lacraig2]

Summary

• add the qemu_mem plugin to suballocate native mmap regions from a single QEMU aperture
• plumb native mmap physical addresses into devfs, procfs, and anonfs when qemu_mem is loaded while preserving the legacy fallback otherwise
• add native mmap smoke coverage for /dev, /proc, anonfs, and MTD registration/read-write, and fix --test-file forwarding in the target test harness
• use 0x90000000 in the smoke config because 0xfe000000 collides with PC machine MMIO on the focused x86_64 smoke

Dependency

• depends on penguin: add native mmap aperture MMIO hooks qemu#1

Testing

• flake8
• python3 -m py_compile pyplugins/compat/qemu_compat.py pyplugins/hyperfile/qemu_mem.py pyplugins/hyperfile/devfs.py pyplugins/hyperfile/procfs.py pyplugins/hyperfile/anonfs.py pyplugins/testing/native_mmap.py tests/unit_tests/test_target/test.py
• tests/unit_tests/test_target/test.py --kernel 4.10 --arch x86_64 --image penguin-native-mmap-smoke --test-file native_mmap.yaml --mode kvm --name native_mmap_smoke_mainbase
• tests/unit_tests/test_target/test.py --kernel 4.10 --arch x86_64 --image penguin-native-mmap-smoke --test-file devfs_test.yaml --mode kvm --name devfs_mmap_regression_mainbase
• tests/unit_tests/test_target/test.py --kernel 4.10 --arch x86_64 --image penguin-native-mmap-smoke --test-file procfs_test.yaml --mode kvm --name procfs_mmap_regression_mainbase