Add assert() to quiet Clang scan-build warnings

In ProcessUNIX.c, testProcess.c, and testCommandLineArguments1.cxx, add
assert() calls to tell Clang scan-build that we do not expect certain
pointers to be NULL.

Change-Id: I4a2b035cf58198606b4698c9d0e2048a66f15fd0

ProcessUNIX.c

@@ -68,6 +68,7 @@ do.
 #include <signal.h>    /* sigaction */
 #include <dirent.h>    /* DIR, dirent */
 #include <ctype.h>     /* isspace */
+#include <assert.h>    /* assert */
 
 #if defined(__VMS)
 # define KWSYSPE_VMS_NONBLOCK , O_NONBLOCK
@@ -450,6 +451,7 @@ int kwsysProcess_AddCommand(kwsysProcess* cp, char const* const* command)
       }
     for(i=0; i < n; ++i)
       {
+      assert(command[i]); /* Quiet Clang scan-build. */
       newCommands[cp->NumberOfCommands][i] = strdup(command[i]);
       if(!newCommands[cp->NumberOfCommands][i])
         {

testCommandLineArguments1.cxx

@@ -21,6 +21,7 @@
 # include "kwsys_ios_iostream.h.in"
 #endif
 
+#include <assert.h> /* assert */
 #include <string.h> /* strcmp */
 
 int testCommandLineArguments1(int argc, char* argv[])
@@ -83,6 +84,7 @@ int testCommandLineArguments1(int argc, char* argv[])
     }
   for ( cc = 0; cc < newArgc; ++ cc )
     {
+    assert(newArgv[cc]); /* Quiet Clang scan-build. */
     kwsys_ios::cout << "Unused argument[" << cc << "] = [" << newArgv[cc] << "]"
       << kwsys_ios::endl;
     if ( cc >= 9 )

testProcess.c

@@ -20,6 +20,7 @@
 # include "Encoding.h.in"
 #endif
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -104,6 +105,7 @@ static int test4(int argc, const char* argv[])
   fprintf(stderr, "Output before crash on stderr from crash test.\n");  
   fflush(stdout);
   fflush(stderr);
+  assert(invalidAddress); /* Quiet Clang scan-build. */
   /* Provoke deliberate crash by writing to the invalid address. */
   *invalidAddress = 0;
   fprintf(stdout, "Output after crash on stdout from crash test.\n");