[llvm] Unittests and usability for BitstreamWriter incremental flushing (PR #92983)

[Teresa Johnson via llvm-commits]

================
@@ -5093,7 +5093,7 @@ void llvm::WriteBitcodeToFile(const Module &M, raw_ostream &Out,
   if (TT.isOSDarwin() || TT.isOSBinFormatMachO()) {
     // If this is darwin or another generic macho target, reserve space for the
     // header. Note that the header is computed *after* the output is known, so
-    // we currently expliclty use a buffer, write to it, and then subsequently
+    // we currently explicilty use a buffer, write to it, and then subsequently
----------------
teresajohnson wrote:

still a typo in that word =)

https://github.com/llvm/llvm-project/pull/92983