Minor warnings fixes.

imgui.cpp

@@ -6274,7 +6274,7 @@ bool ImGui::SliderBehavior(const ImRect& frame_bb, ImGuiID id, float* v, float v
                 {
                     // Positive: rescale to the positive range before powering
                     float a;
-                    if (fabsf(linear_zero_pos - 1.0f) > 1.e-6)
+                    if (fabsf(linear_zero_pos - 1.0f) > 1.e-6f)
                         a = (normalized_pos - linear_zero_pos) / (1.0f - linear_zero_pos);
                     else
                         a = normalized_pos;

stb_rect_pack.h

@@ -268,9 +268,9 @@ STBRP_DEF void stbrp_init_target(stbrp_context *context, int width, int height,
 }
 
 // find minimum y position if it starts at x1
-static int stbrp__skyline_find_min_y(stbrp_context *c, stbrp_node *first, int x0, int width, int *pwaste)
+static int stbrp__skyline_find_min_y(stbrp_context *, stbrp_node *first, int x0, int width, int *pwaste)
 {
-   (void)c;
+   //(void)c;
    stbrp_node *node = first;
    int x1 = x0 + width;
    int min_y, visited_width, waste_area;