Remove mentions of long removed function. (#118509)

Author: AaronRobinsonMSFT

src/coreclr/utilcode/utsem.cpp

@@ -195,7 +195,7 @@ HRESULT UTSemReadWrite::LockRead()
     // holding this lock.
     IncCantStopCount();
 
-    // First do some spinning - copied from file:..\VM\crst.cpp#CrstBase::SpinEnter
+    // First do some spinning
     for (DWORD iter = 0; iter < g_SpinConstants.dwRepetitions; iter++)
     {
         DWORD i = g_SpinConstants.dwInitialDuration;
@@ -287,7 +287,7 @@ HRESULT UTSemReadWrite::LockWrite()
     // holding this lock.
     IncCantStopCount();
 
-    // First do some spinning - copied from file:..\VM\crst.cpp#CrstBase::SpinEnter
+    // First do some spinning
     for (DWORD iter = 0; iter < g_SpinConstants.dwRepetitions; iter++)
     {
         DWORD i = g_SpinConstants.dwInitialDuration;

src/coreclr/vm/crst.h

@@ -168,8 +168,6 @@ class CrstBase
     void Enter(INDEBUG(NoLevelCheckFlag noLevelCheckFlag = CRST_LEVEL_CHECK));
     void Leave();
 
-    void SpinEnter();
-
 #ifndef DACCESS_COMPILE
     DEBUG_NOINLINE static void AcquireLock(CrstBase *c) {
         WRAPPER_NO_CONTRACT;