[llvm] [llvm][ELF] Add statistics on various section sizes (PR #102363)

[Fangrui Song via llvm-commits]

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@@ -0,0 +1,10 @@
+; REQUIRES: asserts
+; RUN: llc -o /dev/null -filetype=obj -stats %s 2>&1 | FileCheck %s
+
+; CHECK: {{[0-9+]}} elf-object-writer - Total size of SHF_ALLOC text sections
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MaskRay wrote:

`[[#]]`. I think it's fine to test the exact number to ensure that we don't regress.

You can add a variable and test SHF_WRITE as well. 

https://github.com/llvm/llvm-project/pull/102363