[llvm] [CAS] Add MappedFileRegionBumpPtr (PR #114099)

[Adrian Prantl via llvm-commits]

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@@ -146,4 +146,7 @@
    coverage bugs, and to 0 otherwise. */
 #cmakedefine01 LLVM_ENABLE_DEBUGLOC_TRACKING_ORIGIN
 
+/* Define to 1 to enable LLVM OnDisk Content Addressable Storage*/
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adrian-prantl wrote:

```suggestion
/* Define to 1 to enable LLVM OnDisk Content Addressable Storage */
```

https://github.com/llvm/llvm-project/pull/114099