[llvm] Add the 'initializes' attribute langref and support (PR #84803)

[Arthur Eubanks via llvm-commits]

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@@ -616,6 +661,23 @@ std::string Attribute::getAsString(bool InAttrGrp) const {
     return Result;
   }
 
+  if (hasAttribute(Attribute::Initializes)) {
+    std::string Result;
+    raw_string_ostream OS(Result);
+    ConstantRangeList CRL = getValueAsConstantRangeList();
+    OS << "initializes(";
+    size_t i = 0;
+    for (auto &CR : CRL) {
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aeubanks wrote:

use the recently introduced `interleaveComma`

https://github.com/llvm/llvm-project/pull/84803