[core] Fix build when building Qt Location plugin for Android

- log2 is not available on Android before API 18.
- Android doesn't have 'round' on the std:: namespace when using g++.

Co-authored-by: Thiago Marcos P. Santos <thiago@mapbox.com>

src/mbgl/renderer/buckets/symbol_bucket.cpp

@@ -193,8 +193,8 @@ void SymbolBucket::sortFeatures(const float angle) {
     std::sort(symbolInstanceIndexes.begin(), symbolInstanceIndexes.end(), [sin, cos, this](size_t &aIndex, size_t &bIndex) {
         const SymbolInstance& a = symbolInstances[aIndex];
         const SymbolInstance& b = symbolInstances[bIndex];
-        const int32_t aRotated = static_cast<int32_t>(std::lround(sin * a.anchor.point.x + cos * a.anchor.point.y));
-        const int32_t bRotated = static_cast<int32_t>(std::lround(sin * b.anchor.point.x + cos * b.anchor.point.y));
+        const int32_t aRotated = static_cast<int32_t>(::lround(sin * a.anchor.point.x + cos * a.anchor.point.y));
+        const int32_t bRotated = static_cast<int32_t>(::lround(sin * b.anchor.point.x + cos * b.anchor.point.y));
         return aRotated != bRotated ?
             aRotated < bRotated :
             a.dataFeatureIndex > b.dataFeatureIndex;

src/mbgl/util/tile_cover.cpp

@@ -4,6 +4,7 @@
 #include <mbgl/map/transform_state.hpp>
 #include <mbgl/util/tile_cover_impl.hpp>
 #include <mbgl/util/tile_coordinate.hpp>
+#include <mbgl/math/log2.hpp>
 
 #include <functional>
 #include <list>