[llvm] [BPF] Use ".L" local prefix label for basic blocks (PR #95103)

[via llvm-commits]

yonghong-song wrote:

Okay, looks like consensus is to use '.L' prefix for private global prefix and private label prefix. @aengelke could you make the change again? The below should work:
```
diff --git a/llvm/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h b/llvm/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h
index 7b2168458c93..1173fe2f7590 100644
--- a/llvm/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h
+++ b/llvm/lib/Target/BPF/MCTargetDesc/BPFMCAsmInfo.h
@@ -25,6 +25,7 @@ public:
       IsLittleEndian = false;
 
     PrivateGlobalPrefix = ".L";
+    PrivateLabelPrefix = ".L";
     WeakRefDirective = "\t.weak\t";
```

https://github.com/llvm/llvm-project/pull/95103