Merge pull request #3854 from nbdd0121/patch-1

Clarify that `__vectorcall` is still decorated in x64

Author: Colin Robertson

docs/build/reference/decorated-names.md

@@ -47,7 +47,7 @@ The function and class names are encoded in the decorated name. The rest of the
 
 ## <a name="FormatC"></a> Format of a C decorated name
 
-The form of decoration for a C function depends on the calling convention used in its declaration, as shown in the following table. This is also the decoration format that is used when C++ code is declared to have `extern "C"` linkage. The default calling convention is **`__cdecl`**. Note that in a 64-bit environment, functions are not decorated.
+The form of decoration for a C function depends on the calling convention used in its declaration, as shown in the following table. It's also the decoration format that's used when C++ code is declared to have `extern "C"` linkage. The default calling convention is **`__cdecl`**. In a 64-bit environment, C or `extern "C"` functions are only decorated when using the `__vectorcall` calling convention.
 
 |Calling convention|Decoration|
 |------------------------|----------------|