Fix linkage conflict warning/error on MinGW and MSVC.

src/Magnum/MeshView.h

@@ -164,7 +164,8 @@ class MAGNUM_EXPORT MeshView {
          * available there.
          * @see @ref setCount()
          */
-        MeshView& setIndexRange(Int first, UnsignedInt start, UnsignedInt end);
+        /* MinGW/MSVC needs inline also here to avoid linkage conflicts */
+        inline MeshView& setIndexRange(Int first, UnsignedInt start, UnsignedInt end);
 
         #ifdef MAGNUM_BUILD_DEPRECATED
         /**

src/Magnum/Shaders/Flat.h

@@ -200,7 +200,8 @@ template<UnsignedInt dimensions> class MAGNUM_SHADERS_EXPORT Flat: public Abstra
          * multiplied with texture if @ref Flag::Textured is set.
          * @see @ref setTexture()
          */
-        Flat<dimensions>& setColor(const Color4& color);
+        /* MSVC needs inline also here to avoid linkage conflicts */
+        inline Flat<dimensions>& setColor(const Color4& color);
 
         /**
          * @brief Set texture