Add compatibility option to force flushing to zero

This prevents Kush Audio REDDI from taking down the DAW when the host
passes it denormalized audio to process. I've discovered that the issue
with this plugin had to do with denormals in the issue linked below, but
I didn't realize that we can just enable the FTZ flag for plugins that
don't already do so.

https://github.com/osxmidi/LinVst/issues/174

CHANGELOG.md

@@ -16,6 +16,15 @@ Versioning](https://semver.org/spec/v2.0.0.html).
   that have undesirable or broken DAW-specific behaviour. See the [known
   issues](https://github.com/robbert-vdh/yabridge#runtime-dependencies-and-known-issues)
   section of the readme for more information on when this may be useful.
+- Added another new [compatibility
+  option](https://github.com/robbert-vdh/yabridge#compatibility-options) to
+  force flushing denormals to zero during audio processing. Some plugins, such
+  as _Kush Audio REDDI_, have significantly increased DSP usage when processing
+  audio that's almost but not quite silent. When this happens, you will notice
+  that a plugin's DSP usage increases exponentially after playback has stopped
+  or when the plugin starts processing silence. Enabling this new option will
+  force your CPU to flush this almost silent audio to silence, potentially
+  fixing the issue.
 
 ### Changed