Make it clear that include scanning is disabled in Bazel.
This is so that bugs like won't
get filed again.
RELNOTES: None.
@@ -1064,7 +1064,8 @@ the set of inputs of an action come in two forms:
header file as an "input", but scan the source file for transitively
included headers and only mark those header files as inputs that are
mentioned in `#include` statements (we overestimate so that we don't need to
- implement a full C preprocessor)
+ implement a full C preprocessor) This option is currently hard-wired to
+ "false" in Bazel and is only used at Google.
* An action may realize that some files were not used during its execution. In
C++, this is called ".d files": the compiler tells which header files were
used after the fact, and in order to avoid the embarrassment of having worse
