Modernize macros to use do { } while (0)

This PR introduces no functional changes. It attempts to change all
macros currently using `{ }` or some variant of that to to
`do { } while (0)`, and introduces trailing `;` where necessary.
There were no bugs found during this migration.

The bug in Visual Studios warning on this has been fixed since VS2015.
Additionally, we have several instances of `do { } while (0)` which have
been present for several releases, so we don't have to worry about
breaking peoples builds.

Fixes Issue #3830.

lib/decompress/zstd_decompress.c

@@ -2173,7 +2173,7 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
                     /* shortcut : using single-pass mode */
                     size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, (size_t)(oend-op), istart, cSize, ZSTD_getDDict(zds));
                     if (ZSTD_isError(decompressedSize)) return decompressedSize;
-                    DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()")
+                    DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()");
                     assert(istart != NULL);
                     ip = istart + cSize;
                     op = op ? op + decompressedSize : op; /* can occur if frameContentSize = 0 (empty frame) */