bpo-44458: Ensure BUFFER_BLOCK_SIZE symbol is statically allocated. (GH-26808) (GH-26844)

* bpo-44458: Ensure BUFFER_BLOCK_SIZE symbol is statically allocated.
(cherry picked from commit 92c2e91580521ba5c85aa3205a0211df5b48689b)

Co-authored-by: Russell Keith-Magee <[email protected]>

Author: miss-islington

Include/internal/pycore_blocks_output_buffer.h

@@ -57,7 +57,7 @@ static const char unable_allocate_msg[] = "Unable to allocate output buffer.";
 /* Block size sequence */
 #define KB (1024)
 #define MB (1024*1024)
-const Py_ssize_t BUFFER_BLOCK_SIZE[] =
+static const Py_ssize_t BUFFER_BLOCK_SIZE[] =
     { 32*KB, 64*KB, 256*KB, 1*MB, 4*MB, 8*MB, 16*MB, 16*MB,
       32*MB, 32*MB, 32*MB, 32*MB, 64*MB, 64*MB, 128*MB, 128*MB,
       OUTPUT_BUFFER_MAX_BLOCK_SIZE };

Misc/NEWS.d/next/Library/2021-06-20-07-14-46.bpo-44458.myqCQ0.rst

@@ -0,0 +1 @@
+``BUFFER_BLOCK_SIZE`` is now declared static, to avoid linking collisions when bz2, lmza or zlib are statically linked.