fix build using Watcom :

./src/render/SDL_render.c(2168): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2168): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2175): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2175): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant

./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant

src/render/SDL_render.c

@@ -2165,14 +2165,18 @@ SDL_RenderClear(SDL_Renderer * renderer)
 int
 SDL_RenderDrawPoint(SDL_Renderer * renderer, int x, int y)
 {
-    const SDL_FPoint fpoint = { (float) x, (float) y };
+    SDL_FPoint fpoint;
+    fpoint.x = (float) x;
+    fpoint.y = (float) y;
     return SDL_RenderDrawPointsF(renderer, &fpoint, 1);
 }
 
 int
 SDL_RenderDrawPointF(SDL_Renderer * renderer, float x, float y)
 {
-    const SDL_FPoint fpoint = { x, y };
+    SDL_FPoint fpoint;
+    fpoint.x = x;
+    fpoint.y = y;
     return SDL_RenderDrawPointsF(renderer, &fpoint, 1);
 }
 
@@ -2319,14 +2323,22 @@ SDL_RenderDrawPointsF(SDL_Renderer * renderer,
 int
 SDL_RenderDrawLine(SDL_Renderer * renderer, int x1, int y1, int x2, int y2)
 {
-    const SDL_FPoint points[2] = { { (float) x1, (float) y1 }, { (float) x2, (float) y2 } };
+    SDL_FPoint points[2];
+    points[0].x = (float) x1;
+    points[0].y = (float) y1;
+    points[1].x = (float) x2;
+    points[1].y = (float) y2;
     return SDL_RenderDrawLinesF(renderer, points, 2);
 }
 
 int
 SDL_RenderDrawLineF(SDL_Renderer * renderer, float x1, float y1, float x2, float y2)
 {
-    const SDL_FPoint points[2] = { { x1, y1 }, { x2, y2 } };
+    SDL_FPoint points[2];
+    points[0].x = x1;
+    points[0].y = y1;
+    points[1].x = x2;
+    points[1].y = y2;
     return SDL_RenderDrawLinesF(renderer, points, 2);
 }
 

src/render/software/SDL_render_sw.c

@@ -599,7 +599,11 @@ SW_RunCommandQueue(SDL_Renderer * renderer, SDL_RenderCommand *cmd, void *vertic
                 SDL_assert(viewport != NULL);
                 cliprect = cmd->data.cliprect.enabled ? &cmd->data.cliprect.rect : NULL;
                 if (cliprect) {
-                    SDL_Rect clip_rect = { cliprect->x + viewport->x, cliprect->y + viewport->y, cliprect->w, cliprect->h };
+                    SDL_Rect clip_rect;
+                    clip_rect.x = cliprect->x + viewport->x;
+                    clip_rect.y = cliprect->y + viewport->y;
+                    clip_rect.w = cliprect->w;
+                    clip_rect.h = cliprect->h;
                     SDL_IntersectRect(viewport, &clip_rect, &clip_rect);
                     SDL_SetClipRect(surface, &clip_rect);
                 } else {