Rollup merge of #122326 - Zoxc:win-alloc-tweak, r=ChrisDenton

Optimize `process_heap_alloc`

This optimizes `process_heap_alloc` introduced in rust-lang/rust#120205.

From:
```
.text:0000000180027ED0 ; std::sys::pal::windows::alloc::process_heap_alloc::h703a613b3e25ff93
.text:0000000180027ED0                 public _ZN3std3sys3pal7windows5alloc18process_heap_alloc17h703a613b3e25ff93E
.text:0000000180027ED0 _ZN3std3sys3pal7windows5alloc18process_heap_alloc17h703a613b3e25ff93E proc near
.text:0000000180027ED0                                         ; CODE XREF: std::sys::pal::common::alloc::realloc_fallback::hc4c96b4c24d03e77+23↑p
.text:0000000180027ED0                                         ; std::sys::pal::common::alloc::realloc_fallback::hc4c96b4c24d03e77+55↑p ...
.text:0000000180027ED0                 push    rsi
.text:0000000180027ED1                 push    rdi
.text:0000000180027ED2                 sub     rsp, 28h
.text:0000000180027ED6                 mov     rsi, rdx
.text:0000000180027ED9                 mov     edi, ecx
.text:0000000180027EDB                 mov     rcx, cs:_ZN3std3sys3pal7windows5alloc4HEAP17hb53ca4010cc29b62E ; std::sys::pal::windows::alloc::HEAP::hb53ca4010cc29b62
.text:0000000180027EE2                 test    rcx, rcx
.text:0000000180027EE5                 jnz     short loc_180027EFC
.text:0000000180027EE7                 call    cs:__imp_GetProcessHeap
.text:0000000180027EED                 test    rax, rax
.text:0000000180027EF0                 jz      short loc_180027F0E
.text:0000000180027EF2                 mov     rcx, rax
.text:0000000180027EF5                 mov     cs:_ZN3std3sys3pal7windows5alloc4HEAP17hb53ca4010cc29b62E, rax ; std::sys::pal::windows::alloc::HEAP::hb53ca4010cc29b62
.text:0000000180027EFC
.text:0000000180027EFC loc_180027EFC:                          ; CODE XREF: std::sys::pal::windows::alloc::process_heap_alloc::h703a613b3e25ff93+15↑j
.text:0000000180027EFC                 mov     edx, edi
.text:0000000180027EFE                 mov     r8, rsi
.text:0000000180027F01                 add     rsp, 28h
.text:0000000180027F05                 pop     rdi
.text:0000000180027F06                 pop     rsi
.text:0000000180027F07                 jmp     cs:__imp_HeapAlloc
.text:0000000180027F0E ; ---------------------------------------------------------------------------
.text:0000000180027F0E
.text:0000000180027F0E loc_180027F0E:                          ; CODE XREF: std::sys::pal::windows::alloc::process_heap_alloc::h703a613b3e25ff93+20↑j
.text:0000000180027F0E                 xor     eax, eax
.text:0000000180027F10                 add     rsp, 28h
.text:0000000180027F14                 pop     rdi
.text:0000000180027F15                 pop     rsi
.text:0000000180027F16                 retn
.text:0000000180027F16 _ZN3std3sys3pal7windows5alloc18process_heap_alloc17h703a613b3e25ff93E endp
```
to
```
.text:0000000180027EE0 ; std::sys::pal::windows::alloc::process_heap_alloc::h70f9d61a631e5c16
.text:0000000180027EE0                 public _ZN3std3sys3pal7windows5alloc18process_heap_alloc17h70f9d61a631e5c16E
.text:0000000180027EE0 _ZN3std3sys3pal7windows5alloc18process_heap_alloc17h70f9d61a631e5c16E proc near
.text:0000000180027EE0                                         ; CODE XREF: std::sys::pal::common::alloc::realloc_fallback::hc4c96b4c24d03e77+23↑p
.text:0000000180027EE0                                         ; std::sys::pal::common::alloc::realloc_fallback::hc4c96b4c24d03e77+54↑p ...
.text:0000000180027EE0                 mov     rcx, cs:_ZN3std3sys3pal7windows5alloc4HEAP17hb53ca4010cc29b62E ; std::sys::pal::windows::alloc::HEAP::hb53ca4010cc29b62
.text:0000000180027EE7                 test    rcx, rcx
.text:0000000180027EEA                 jz      short loc_180027EF3
.text:0000000180027EEC                 jmp     cs:__imp_HeapAlloc
.text:0000000180027EF3 ; ---------------------------------------------------------------------------
.text:0000000180027EF3
.text:0000000180027EF3 loc_180027EF3:                          ; CODE XREF: std::sys::pal::windows::alloc::process_heap_alloc::h70f9d61a631e5c16+A↑j
.text:0000000180027EF3                 mov     ecx, edx
.text:0000000180027EF5                 mov     rdx, r8
.text:0000000180027EF8                 jmp     std__sys__pal__windows__alloc__process_heap_init_and_alloc
.text:0000000180027EF8 _ZN3std3sys3pal7windows5alloc18process_heap_alloc17h70f9d61a631e5c16E endp
```

r? `@ChrisDenton`