Driver-related patches (dropped at every major release if they are not yet upstream):
 - UBUNTU: SAUCE: Revert "fbdev: Make registered_fb[] private to fbmem.c" (required by nvidia, plan was to drop in newer kernels)

Ubuntu-specific features not supported anymore:
 - UBUNTU: SAUCE: shiftfs: deprecated
 - UBUNTU: SAUCE: ubuntu fan: deprecated

Retpoline annotations reverted after enforcing objtool warnings as fatal (LP: #2046440):
 - UBUNTU: SAUCE: apm -- annotate indirect calls within firmware_restrict_branch_speculation_{start,end}
 - UBUNTU: SAUCE: early/late -- annotate indirect calls in early/late initialisation code
 - UBUNTU: SAUCE: vga_set_mode -- avoid jump tables