dtool: Undo a few changes to dtoolbase that aren't strictly necessary, to better parallel upstream.

dtool/src/cppparser/cppBison.yxx

@@ -195,7 +195,7 @@ pop_struct() {
 /* This is a bison-specific declaration to enable recursive calls to
    yyparse().  It changes the calling sequence to yylex(), passing
    pointers to the current yylval and yylloc. */
-%pure-parser
+%pure_parser
 
 %token <u.real> REAL
 %token <u.integer> INTEGER

dtool/src/dtoolbase/dlmalloc.h

@@ -148,15 +148,9 @@ void* dlvalloc(size_t);
 */
 int dlmallopt(int, int);
 
-#ifndef M_TRIM_THRESHOLD
 #define M_TRIM_THRESHOLD     (-1)
-#endif
-
 #define M_GRANULARITY        (-2)
-
-#ifndef M_MMAP_THRESHOLD
 #define M_MMAP_THRESHOLD     (-3)
-#endif
 
 
 /*

dtool/src/dtoolbase/dlmalloc_src.cxx

@@ -597,15 +597,9 @@ DEFAULT_MMAP_THRESHOLD       default: 256K
   malloc does support the following options.
 */
 
-#ifndef M_TRIM_THRESHOLD
 #define M_TRIM_THRESHOLD     (-1)
-#endif
-
 #define M_GRANULARITY        (-2)
-
-#ifndef M_MMAP_THRESHOLD
 #define M_MMAP_THRESHOLD     (-3)
-#endif
 
 /* ------------------------ Mallinfo declarations ------------------------ */
 
@@ -1186,7 +1180,6 @@ int mspace_mallopt(int, int);
 #include <assert.h>
 #endif /* ABORT_ON_ASSERT_FAILURE */
 #else  /* DEBUG */
-#undef assert
 #define assert(x)
 #endif /* DEBUG */
 #ifndef LACKS_STRING_H

dtool/src/dtoolbase/dtoolbase.h

@@ -104,21 +104,9 @@
 #endif
 
 #ifdef HAVE_PYTHON
-#  undef _POSIX_C_SOURCE
-#  undef _XOPEN_SOURCE
-// Some versions of python also define HAVE_LOCKF
-#  ifdef HAVE_LOCKF
-#    define PANDA_HAVE_LOCKF
-#    undef HAVE_LOCKF
-#  endif
-#  include "pyconfig.h"
-// Restore our HAVE_LOCKF if python didn't define it
-#  ifdef PANDA_HAVE_LOCKF
-#    undef PANDA_HAVE_LOCKF
-#    ifndef HAVE_LOCKF
-#      define HAVE_LOCKF 1
-#    endif
-#  endif
+#undef _POSIX_C_SOURCE
+#undef _XOPEN_SOURCE
+#include "pyconfig.h"
 #endif
 
 #ifndef HAVE_EIGEN