[llvm] [DebugInfo] Don't emit .loc directive with all values zero (PR #109978)

[Oliver Stannard via llvm-commits]

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@@ -0,0 +1,27 @@
+; RUN: llc -mtriple=arm-none-eabi < %s | FileCheck %s
+; RUN: llc -mtriple=arm-none-eabi < %s | llvm-mc --triple=arm-none-eabi -mcpu=cortex-m3
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ostannard wrote:

It checks for the original way we discovered this problem, which was that `llc` generated assembly which was rejected by the assembly parser.

https://github.com/llvm/llvm-project/pull/109978