Add stub for Math/BitFuncs.h with CountTrailingZeroes32().

src/Math/BitFuncs.h

@@ -0,0 +1,31 @@
+/* Copyright Jukka Jylänki
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
+/** @file BitFuncs.h
+	@author Jukka Jylänki
+	@brief */
+#pragma once
+
+static inline int CountTrailingZeroes32(uint32_t x)
+{
+#ifdef _MSC_VER
+	unsigned long ret;
+	_BitScanForward(&ret, x);
+	return (int)ret;
+#else // TODO: be more precise here
+	return __builtin_ctz(x);
+#endif
+}
+
+// TODO: Other bit twiddling related functions.