Noop loop is only optimized away when the range is half-open

#[no_mangle]
pub fn f() {
    for _ in 0..=100 {
        ()
    }
}

#[no_mangle]
pub fn g() {
    for _ in 0..100 {
        ()
    }
}

with -O gives

f:
        xor     ecx, ecx
        mov     eax, 100
.LBB0_1:
        lea     edx, [rcx + 1]
        cmp     ecx, 100
        mov     ecx, edx
        cmovge  ecx, eax
        jge     .LBB0_3
        cmp     ecx, 101
        jl      .LBB0_1
.LBB0_3:
        ret

g:
        ret

Meta

Exists in both 1.77 and nightly.

<backtrace>

@rustbot label +A-codegen +A-LLVM +C-optimization +I-slow +S-has-mcve +I-heavy +T-compiler -needs-triage