Move a local to the #if block where it is used

[cuviper]

For other cases (LLVM < 17), this was complaining under -Wall:

warning: llvm-wrapper/PassWrapper.cpp: In function ‘void LLVMRustPrintTargetCPUs(LLVMTargetMachineRef, const char*)’:
warning: llvm-wrapper/PassWrapper.cpp:311:26: warning: unused variable ‘MCInfo’ [-Wunused-variable]
warning:   311 |   const MCSubtargetInfo *MCInfo = Target->getMCSubtargetInfo();
warning:       |                          ^~~~~~

[rustbot]

r? @Mark-Simulacrum

(rustbot has picked a reviewer for you, use r? to override)

[Mark-Simulacrum]

@bors r+

[bors]

📌 Commit ef06519 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[bors]

⌛ Testing commit ef06519 with merge d1fb175...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing d1fb175 to master...

[rust-timer]

Finished benchmarking commit (d1fb175): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.0%, 2.8%]	2
Regressions ❌ (secondary)	2.3%	[1.2%, 4.4%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.4%	[2.0%, 2.8%]	2

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.8%	[1.2%, 5.6%]	15
Regressions ❌ (secondary)	1.4%	[1.3%, 1.4%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.8%	[1.2%, 5.6%]	15

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 631.802s -> 631.583s (-0.03%)
Artifact size: 316.10 MiB -> 315.88 MiB (-0.07%)