[mini] Disable passing valuetypes in SIMD registers (#74582)

Partially reverts dotnet/runtime#68991

When LLVM code calls non-LLVM code it will pass arguments in SIMD
registers which the non-LLVM code doesn't expect

Fixes dotnet/runtime#73454 (issue 1)

src/mono/mono/mini/mini-amd64.c

@@ -2165,13 +2165,20 @@ mono_arch_get_llvm_call_info (MonoCompile *cfg, MonoMethodSignature *sig)
 				return linfo;
 			}
 
+#if 0
+			/* FIXME: the non-LLVM codegen should also pass arguments in registers or
+			 * else there could a mismatch when LLVM code calls non-LLVM code
+			 *
+			 * See https://github.com/dotnet/runtime/issues/73454
+			 */
 			if ((t->type == MONO_TYPE_GENERICINST) && !cfg->full_aot && !sig->pinvoke) {
 				MonoClass *klass = mono_class_from_mono_type_internal (t);
 				if (MONO_CLASS_IS_SIMD (cfg, klass)) {
 					linfo->args [i].storage = LLVMArgVtypeInSIMDReg;
 					break;
 				}
 			}
+#endif
 
 			linfo->args [i].storage = LLVMArgVtypeInReg;
 			for (j = 0; j < 2; ++j)

src/mono/mono/mini/mini-arm64.c

@@ -2521,13 +2521,20 @@ mono_arch_get_llvm_call_info (MonoCompile *cfg, MonoMethodSignature *sig)
 			break;
 		}
 		case ArgVtypeInIRegs:
+#if 0
+			/* FIXME: the non-LLVM codegen should also pass arguments in registers or
+			 * else there could a mismatch when LLVM code calls non-LLVM code
+			 *
+			 * See https://github.com/dotnet/runtime/issues/73454
+			 */
 			if ((t->type == MONO_TYPE_GENERICINST) && !cfg->full_aot && !sig->pinvoke) {
 				MonoClass *klass = mono_class_from_mono_type_internal (t);
 				if (MONO_CLASS_IS_SIMD (cfg, klass)) {
 					lainfo->storage = LLVMArgVtypeInSIMDReg;
 					break;
 				}
 			}
+#endif
 
 			lainfo->storage = LLVMArgAsIArgs;
 			lainfo->nslots = ainfo->nregs;