[SIL] Removed SILArgument::isNoImplicitCopy.

The attribute can't be applied to non-function arguments and may cause
confusion by being available on them.

Author: nate-chandler

include/swift/SIL/SILArgument.h

@@ -113,8 +113,6 @@ class SILArgument : public ValueBase {
            node->getKind() <= SILNodeKind::Last_SILArgument;
   }
 
-  bool isNoImplicitCopy() const;
-
   unsigned getIndex() const;
 
   /// Return non-null if \p value is a phi.
@@ -408,12 +406,6 @@ inline SILPhiArgument *SILArgument::isTerminatorResult(SILValue value) {
   return nullptr;
 }
 
-inline bool SILArgument::isNoImplicitCopy() const {
-  if (auto *fArg = dyn_cast<SILFunctionArgument>(this))
-    return fArg->isNoImplicitCopy();
-  return false;
-}
-
 inline bool SILArgument::isTerminatorResult() const {
   switch (getKind()) {
   case SILArgumentKind::SILPhiArgument:

lib/Serialization/SerializeSIL.cpp

@@ -624,7 +624,9 @@ void SILSerializer::writeSILBasicBlock(const SILBasicBlock &BB) {
     unsigned packedMetadata = 0;
     packedMetadata |= unsigned(SA->getType().getCategory());  // 8 bits
     packedMetadata |= unsigned(SA->getOwnershipKind()) << 8;  // 8 bits
-    packedMetadata |= unsigned(SA->isNoImplicitCopy()) << 16; // 1 bit
+    if (auto *SFA = dyn_cast<SILFunctionArgument>(SA)) {
+      packedMetadata |= unsigned(SFA->isNoImplicitCopy()) << 16; // 1 bit
+    }
     // Used: 17 bits. Free: 15.
     //
     // TODO: We should be able to shrink the packed metadata of the first two.