PPU Loader: Fix main()'s envp, move process arguments to stack

[elad335]

This originally came from that I knew for a while that R1 of main thread is not accurate to realh unlike in other threads, I did not fix it originally when discovered because I was not sure why R1 changes sometimes.
Today it hitted me that it may because the argv and envp are passed on the stack and their size may differ when using different arguments.
So I tested it on realhw, fixing it by moving argv and envp to stack instead of dynamic memory. Saving a whopping 128KB of RAM as a side effect ;)
But this was not playing nice with envp, after some reversing it turned out we were emulating envp wrong.
Originally, the argv and envp pointer arrays are 64-bit arrays because CELL is natively a 64-bit processor, but games use 32-bit pointers exclusively. So the workaround embedded in all EBOOT.BIN is to convert the 64-bit array into 32-bit array. This functionality needs to know how many arguments are in each array in total. Total amount of envp arguments is passed in the R6 register to the program but we were always initializaing it with 0 so it could not fix the envp array resutling in crashes (because it always pointed to 32-bit nullptr) when dereferencing it!

Hwtest: elad335/myps3tests@173d346

Fixes #13014 as it turns out :)

[MastaG]

Awesome work there!

[capriots]

Fixes #13014