stb_image_write: add missing 'static' on internal functions

stb_image_write.h

@@ -602,7 +602,7 @@ STBIWDEF int stbi_write_tga(char const *filename, int x, int y, int comp, const
 
 #define stbiw__max(a, b)  ((a) > (b) ? (a) : (b))
 
-void stbiw__linear_to_rgbe(unsigned char *rgbe, float *linear)
+static void stbiw__linear_to_rgbe(unsigned char *rgbe, float *linear)
 {
    int exponent;
    float maxcomp = stbiw__max(linear[0], stbiw__max(linear[1], linear[2]));
@@ -619,7 +619,7 @@ void stbiw__linear_to_rgbe(unsigned char *rgbe, float *linear)
    }
 }
 
-void stbiw__write_run_data(stbi__write_context *s, int length, unsigned char databyte)
+static void stbiw__write_run_data(stbi__write_context *s, int length, unsigned char databyte)
 {
    unsigned char lengthbyte = STBIW_UCHAR(length+128);
    STBIW_ASSERT(length+128 <= 255);
@@ -627,7 +627,7 @@ void stbiw__write_run_data(stbi__write_context *s, int length, unsigned char dat
    s->func(s->context, &databyte, 1);
 }
 
-void stbiw__write_dump_data(stbi__write_context *s, int length, unsigned char *data)
+static void stbiw__write_dump_data(stbi__write_context *s, int length, unsigned char *data)
 {
    unsigned char lengthbyte = STBIW_UCHAR(length);
    STBIW_ASSERT(length <= 128); // inconsistent with spec but consistent with official code
@@ -635,7 +635,7 @@ void stbiw__write_dump_data(stbi__write_context *s, int length, unsigned char *d
    s->func(s->context, data, length);
 }
 
-void stbiw__write_hdr_scanline(stbi__write_context *s, int width, int ncomp, unsigned char *scratch, float *scanline)
+static void stbiw__write_hdr_scanline(stbi__write_context *s, int width, int ncomp, unsigned char *scratch, float *scanline)
 {
    unsigned char scanlineheader[4] = { 2, 2, 0, 0 };
    unsigned char rgbe[4];
@@ -859,7 +859,7 @@ static unsigned int stbiw__zhash(unsigned char *data)
 
 #endif // STBIW_ZLIB_COMPRESS
 
-unsigned char * stbi_zlib_compress(unsigned char *data, int data_len, int *out_len, int quality)
+STBIWDEF unsigned char * stbi_zlib_compress(unsigned char *data, int data_len, int *out_len, int quality)
 {
 #ifdef STBIW_ZLIB_COMPRESS
    // user provided a zlib compress implementation, use that
@@ -1075,7 +1075,7 @@ static void stbiw__encode_png_line(unsigned char *pixels, int stride_bytes, int
    }
 }
 
-unsigned char *stbi_write_png_to_mem(const unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len)
+STBIWDEF unsigned char *stbi_write_png_to_mem(const unsigned char *pixels, int stride_bytes, int x, int y, int n, int *out_len)
 {
    int force_filter = stbi_write_force_png_filter;
    int ctype[5] = { -1, 0, 4, 2, 6 };