Cleanup block stores and test for 24846 (#24950)

* Cleanup block stores and test for 24846

Fix zero-length assert/bad codegen for initblk.
Remove redundant assertions in codegen and those that don't directly relate to codegen requirements.
Eliminate redundant LEA that was being generated by `genCodeForCpBlk`.
Rename `genCodeFor[Cp|Init]Blk` to `genCodeFor[Cp|Init]BlkHelper` to parallel the other forms.
Fix the test case for #24846.

1 files changed, 2 insertions, 11 deletions

diff --git a/src/jit/morph.cpp b/src/jit/morph.cpp
index 3bfca379a8..5c13c2bc1a 100644
--- a/src/jit/morph.cpp
+++ b/src/jit/morph.cpp
@@ -9478,16 +9478,7 @@ GenTree* Compiler::fgMorphInitBlock(GenTree* tree)
         }
         else
         {
-            if (dest->OperIs(GT_DYN_BLK))
-            {
-                blockSize = 0;
-            }
-            else
-            {
-                assert(dest->OperIs(GT_BLK, GT_OBJ));
-                blockSize = dest->AsBlk()->Size();
-                assert(blockSize != 0);
-            }
+            blockSize = dest->AsBlk()->Size();
 
             FieldSeqNode* destFldSeq = nullptr;
             if (dest->AsIndir()->Addr()->IsLocalAddrExpr(this, &destLclNode, &destFldSeq))
@@ -9604,7 +9595,7 @@ GenTree* Compiler::fgMorphPromoteLocalInitBlock(GenTreeLclVar* destLclNode, GenT
 
     if (blockSize == 0)
     {
-        JITDUMP(" size is not known.\n");
+        JITDUMP(" size is zero or unknown.\n");
         return nullptr;
     }