[php-src] PR #23942: IR: Fuse loads from constant addresses that don't fit a displacement

Pull Request: https://github.com/php/php-src/pull/23942 Author: ndossche Should be upstreamed, but I first want to check the address on php On x86-64, a load from a constant address was only fused into its user (e.g. a comparison) if the address fits into a 32-bit displacement. Otherwise, the load was emitted separately into a register. Fuse such loads too and load the address into a temporary register, using the existing constraints of the fused load. For example, the check of EG(vm_interrupt) in JIT code changes from ```asm movabsq $EG(vm_interrupt), %rsi movb (%rsi), %sil testb %sil, %sil jne ... ``` to ```asm movabsq $EG(vm_interrupt), %rsi cmpb $0, (%rsi) jne ... ``` Similar for EG(exception) checks etc.