Revert "Consolidate importer spilling code V2 (dotnet#72744)"

This reverts commit cea17b2.

Author: jakobbotsch

src/coreclr/jit/compiler.h

@@ -3799,8 +3799,11 @@ class Compiler
     Statement* impLastStmt; // The last statement for the current BB.
 
 public:
-    static const unsigned CHECK_SPILL_ALL  = static_cast<unsigned>(-1);
-    static const unsigned CHECK_SPILL_NONE = static_cast<unsigned>(-2);
+    enum
+    {
+        CHECK_SPILL_ALL  = -1,
+        CHECK_SPILL_NONE = -2
+    };
 
     void impBeginTreeList();
     void impEndTreeList(BasicBlock* block, Statement* firstStmt, Statement* lastStmt);
@@ -4000,7 +4003,7 @@ class Compiler
     void impSpillSpecialSideEff();
     void impSpillSideEffect(bool spillGlobEffects, unsigned chkLevel DEBUGARG(const char* reason));
     void impSpillSideEffects(bool spillGlobEffects, unsigned chkLevel DEBUGARG(const char* reason));
-    void impSpillLclRefs(unsigned lclNum, unsigned chkLevel);
+    void impSpillLclRefs(unsigned lclNum);
 
     BasicBlock* impPushCatchArgOnStack(BasicBlock* hndBlk, CORINFO_CLASS_HANDLE clsHnd, bool isSingleBlockFilter);