mesa: Remove unused _mesa_is_alpha_to_coverage_enabled

Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14545>

src/mesa/main/framebuffer.c

@@ -1022,16 +1022,3 @@ _mesa_is_alpha_test_enabled(const struct gl_context *ctx)
    bool buffer0_is_integer = ctx->DrawBuffer->_IntegerBuffers & 0x1;
    return (ctx->Color.AlphaEnabled && !buffer0_is_integer);
 }
-
-/**
- * Is alpha to coverage enabled and applicable to the currently bound
- * framebuffer?
- */
-bool
-_mesa_is_alpha_to_coverage_enabled(const struct gl_context *ctx)
-{
-   bool buffer0_is_integer = ctx->DrawBuffer->_IntegerBuffers & 0x1;
-   return (ctx->Multisample.SampleAlphaToCoverage &&
-           _mesa_is_multisample_enabled(ctx) &&
-           !buffer0_is_integer);
-}

src/mesa/main/framebuffer.h

@@ -149,7 +149,4 @@ _mesa_is_multisample_enabled(const struct gl_context *ctx);
 extern bool
 _mesa_is_alpha_test_enabled(const struct gl_context *ctx);
 
-extern bool
-_mesa_is_alpha_to_coverage_enabled(const struct gl_context *ctx);
-
 #endif /* FRAMEBUFFER_H */