Add some test code

From the deep dark recesses of my hard disc, some Pi 1-era test code for
CPU & DMA driven PWM audio, now updated to run on Pi 2, 3, & 4.

Version 0.86. Tagged as 'HAL_BCM2835-0_86'

VersionNum

-/* (0.85)
+/* (0.86)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  *
  */
-#define Module_MajorVersion_CMHG        0.85
+#define Module_MajorVersion_CMHG        0.86
 #define Module_MinorVersion_CMHG
-#define Module_Date_CMHG                30 May 2020
+#define Module_Date_CMHG                19 Jun 2020
 
-#define Module_MajorVersion             "0.85"
-#define Module_Version                  85
+#define Module_MajorVersion             "0.86"
+#define Module_Version                  86
 #define Module_MinorVersion             ""
-#define Module_Date                     "30 May 2020"
+#define Module_Date                     "19 Jun 2020"
 
-#define Module_ApplicationDate          "30-May-20"
+#define Module_ApplicationDate          "19-Jun-20"
 
 #define Module_ComponentName            "HAL_BCM2835"
 
-#define Module_FullVersion              "0.85"
-#define Module_HelpVersion              "0.85 (30 May 2020)"
-#define Module_LibraryVersionInfo       "0:85"
+#define Module_FullVersion              "0.86"
+#define Module_HelpVersion              "0.86 (19 Jun 2020)"
+#define Module_LibraryVersionInfo       "0:86"