Propagate basic block flags after a failed inline.

This is a fllow-up to dotnet#37335 and dotnet#37840.

When an inline fails we replace `GT_RET_EXPR`with the
original `GT_CALL` node. `GT_RET_EXPR`may end up in
a basic block other than the original `GT_CALL` so we need
to propagate basic block flags.

Fixes dotnet#36588.

src/coreclr/src/jit/compiler.h

@@ -2686,7 +2686,7 @@ class Compiler
     GenTree* gtNewMustThrowException(unsigned helper, var_types type, CORINFO_CLASS_HANDLE clsHnd);
 
     GenTreeLclFld* gtNewLclFldNode(unsigned lnum, var_types type, unsigned offset);
-    GenTree* gtNewInlineCandidateReturnExpr(GenTree* inlineCandidate, var_types type);
+    GenTree* gtNewInlineCandidateReturnExpr(GenTree* inlineCandidate, var_types type, unsigned __int64 bbFlags);
 
     GenTree* gtNewFieldRef(var_types typ, CORINFO_FIELD_HANDLE fldHnd, GenTree* obj = nullptr, DWORD offset = 0);
 

src/coreclr/src/jit/gentree.cpp

@@ -6263,15 +6263,15 @@ GenTreeLclFld* Compiler::gtNewLclFldNode(unsigned lnum, var_types type, unsigned
     return node;
 }
 
-GenTree* Compiler::gtNewInlineCandidateReturnExpr(GenTree* inlineCandidate, var_types type)
+GenTree* Compiler::gtNewInlineCandidateReturnExpr(GenTree* inlineCandidate, var_types type, unsigned __int64 bbFlags)
 {
     assert(GenTree::s_gtNodeSizes[GT_RET_EXPR] == TREE_NODE_SZ_LARGE);
 
     GenTreeRetExpr* node = new (this, GT_RET_EXPR) GenTreeRetExpr(type);
 
     node->gtInlineCandidate = inlineCandidate;
 
-    node->bbFlags = 0;
+    node->bbFlags = bbFlags;
 
     if (varTypeIsStruct(inlineCandidate) && !inlineCandidate->OperIsBlkOp())
     {

src/coreclr/src/jit/importer.cpp

@@ -8809,7 +8809,7 @@ var_types Compiler::impImportCall(OPCODE                  opcode,
                 impAppendTree(call, (unsigned)CHECK_SPILL_ALL, impCurStmtOffs);
 
                 // TODO: Still using the widened type.
-                GenTree* retExpr = gtNewInlineCandidateReturnExpr(call, genActualType(callRetTyp));
+                GenTree* retExpr = gtNewInlineCandidateReturnExpr(call, genActualType(callRetTyp), compCurBB->bbFlags);
 
                 // Link the retExpr to the call so if necessary we can manipulate it later.
                 origCall->gtInlineCandidateInfo->retExpr = retExpr;

src/coreclr/src/jit/indirectcalltransformer.cpp

@@ -738,7 +738,7 @@ class IndirectCallTransformer
             // we set all this up in FixupRetExpr().
             if (oldRetExpr != nullptr)
             {
-                GenTree* retExpr    = compiler->gtNewInlineCandidateReturnExpr(call, call->TypeGet());
+                GenTree* retExpr = compiler->gtNewInlineCandidateReturnExpr(call, call->TypeGet(), thenBlock->bbFlags);
                 inlineInfo->retExpr = retExpr;
 
                 if (returnTemp != BAD_VAR_NUM)