[clang] [LLVM][ADT] Add specialization of `DenseMapInfo` for `SourceRange` (PR #174524)

[Jakub Kuderski via cfe-commits]

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@@ -379,6 +379,20 @@ TEST_F(SourceManagerTest, getInvalidBOM) {
             "UTF-32 (LE)");
 }
 
+TEST_F(SourceManagerTest, sourceRangeWorksWithDenseSet) {
+  llvm::DenseSet<SourceRange> Set;
+  SourceRange TestRange = {SourceLocation::getFromRawEncoding(10),
+                           SourceLocation::getFromRawEncoding(11)};
+  ASSERT_EQ(Set.size(), 0U);
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kuhar wrote:

there's also `testing::IsEmpty` in gmock that solves that, but probably doesn't matter either way here

https://github.com/llvm/llvm-project/pull/174524