Fix lv2_file::file_view::size() and fix SPU cache gen on first boot

[elad335]

• Fixes [Regression] Metal Gear Solid 4 cannot start a new game (#15138) #15209 (lv2_file::file_view::read() regressed)
• Fixes lv2_file::file_view::size() too.
• Avoid changing file position in elf_object::open(), should allow concurrent usage if we ever need it.
• Fix a potential access violation with PPU LLVM builder.
• Prevent using duplicate MSELF entries.
• Fix crash on analyzing invalid code when searching SPU code for the first time.
• Make PPU LLVM compile more MSELF entries by relaxing file name constraints.

[Jonathan44062]

Still black screen when I try to load a save file
RPCS3.log.gz

[Jonathan44062]

Fixed