Add pre_osdi alias and set sourcepath case preservation

- commands.c: register pre_osdi as alias for osdi command so existing
  scripts using pre_osdi continue to work
- inpcom.c: add set sourcepath to the preprocessor case-preservation
  exception list; the lowercasing pass was corrupting uppercase letters
  in paths (e.g. VA_test -> va_test), causing source to fail on
  case-sensitive filesystems

src/frontend/commands.c

@@ -283,6 +283,10 @@ struct comm spcp_coms[] = {
       { 040000, 040000, 040000, 040000 }, E_BEGINNING, 1, LOTS,
       NULL,
       "library library ... : Loads a osdi library." } ,
+    { "pre_osdi", com_osdi, FALSE, TRUE,
+      { 040000, 040000, 040000, 040000 }, E_BEGINNING, 1, LOTS,
+      NULL,
+      "library library ... : Loads a osdi library (alias for osdi)." } ,
 #endif
 #ifdef DEVLIB
     { "use", com_use, FALSE, TRUE,

src/frontend/inpcom.c

@@ -1805,6 +1805,7 @@ static struct inp_read_t inp_read(FILE* fp, int call_depth, const char* dir_name
                     ciprefix("echo", buffer) || ciprefix("shell", buffer) ||
                     ciprefix("source", buffer) || ciprefix("cd", buffer) ||
                     ciprefix("load", buffer) || ciprefix("setcs", buffer) ||
+                    ciprefix("set sourcepath", buffer) ||
                     ciprefix("strcmp", buffer) ||
                     ciprefix("strstr", buffer))))) {
                 /* lower case for all other lines */