Cherry-pick an IRBuilder extension from master (#18138)

* Merge pull request #17988 from apple/rxwei-patch-2

Handle builtin FP types in SILBuilder::appendOperandTypeName

(cherry picked from commit 1609523)

Author: rxwei

include/swift/SIL/SILBuilder.h

@@ -2114,6 +2114,17 @@ class SILBuilder {
         unsigned NumBits = BuiltinIntTy->getWidth().getFixedWidth();
         Name += "_Int" + llvm::utostr(NumBits);
       }
+    } else if (auto BuiltinFloatTy =
+                   dyn_cast<BuiltinFloatType>(OpdTy.getASTType())) {
+      Name += "_FP";
+      switch (BuiltinFloatTy->getFPKind()) {
+      case BuiltinFloatType::IEEE16: Name += "IEEE16"; break;
+      case BuiltinFloatType::IEEE32: Name += "IEEE32"; break;
+      case BuiltinFloatType::IEEE64: Name += "IEEE64"; break;
+      case BuiltinFloatType::IEEE80: Name += "IEEE80"; break;
+      case BuiltinFloatType::IEEE128: Name += "IEEE128"; break;
+      case BuiltinFloatType::PPC128: Name += "PPC128"; break;
+      }
     } else {
       assert(OpdTy.getASTType() == getASTContext().TheRawPointerType);
       Name += "_RawPointer";