[llvm] [Error] Add non-consuming toString (PR #95375)

[Paul T Robinson via llvm-commits]

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@@ -738,17 +738,25 @@ TEST(Error, ErrorCodeConversions) {
 
 // Test that error messages work.
 TEST(Error, ErrorMessage) {
-  EXPECT_EQ(toString(Error::success()), "");
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pogo59 wrote:

I'd want to keep this, just to have one example that doesn't go through toStringWithoutConsuming or visitErrors.

https://github.com/llvm/llvm-project/pull/95375