[llvm] [LLVM][NFC] Remove some global constructors (PR #208407)

[Alexis Engelke via llvm-commits]

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@@ -10,7 +10,7 @@
 
 using namespace llvm;
 
-const OptimizationLevel OptimizationLevel::O0 = {0};
-const OptimizationLevel OptimizationLevel::O1 = {1};
-const OptimizationLevel OptimizationLevel::O2 = {2};
-const OptimizationLevel OptimizationLevel::O3 = {3};
+constexpr OptimizationLevel OptimizationLevel::O0 = {0};
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aengelke wrote:

Agreed, will remove these (replace OptimizationLevel with an enum) in a subsequent PR once this is merged.

https://github.com/llvm/llvm-project/pull/208407