Change prejit instrumentation default back to block profiling

Both crossgen1 and crossgen2 currently reject schemas that contain edge profile
counters. Change the jit defaults back to block profiling when prejitting.

See notes in dotnet#49267.

src/coreclr/jit/fgprofile.cpp

@@ -1489,7 +1489,7 @@ PhaseStatus Compiler::fgPrepareToInstrumentMethod()
     //
     // We enable edge profiling by default, except when:
     // * disabled by option
-    // * we are prejitting via classic ngen
+    // * we are prejitting
     // * we are jitting osr methods
     //
     // Currently, OSR is incompatible with edge profiling. So if OSR is enabled,
@@ -1500,15 +1500,9 @@ PhaseStatus Compiler::fgPrepareToInstrumentMethod()
     //
     CLANG_FORMAT_COMMENT_ANCHOR;
 
-#ifdef FEATURE_READYTORUN_COMPILER
-    const bool r2r = opts.IsReadyToRun();
-#else
-    const bool r2r = false;
-#endif
-    const bool prejit      = opts.jitFlags->IsSet(JitFlags::JIT_FLAG_PREJIT);
-    const bool classicNgen = prejit && !r2r;
-    const bool osr = (opts.jitFlags->IsSet(JitFlags::JIT_FLAG_TIER0) && (JitConfig.TC_OnStackReplacement() > 0));
-    const bool useEdgeProfiles = (JitConfig.JitEdgeProfiling() > 0) && !classicNgen && !osr;
+    const bool prejit = opts.jitFlags->IsSet(JitFlags::JIT_FLAG_PREJIT);
+    const bool osr    = (opts.jitFlags->IsSet(JitFlags::JIT_FLAG_TIER0) && (JitConfig.TC_OnStackReplacement() > 0));
+    const bool useEdgeProfiles = (JitConfig.JitEdgeProfiling() > 0) && !prejit && !osr;
 
     if (useEdgeProfiles)
     {