gdb: Remove duplicate declaration of global innermost_block

The global 'innermost_block' is declared in two header files.  Remove
one of the declarations, and add an include of the other header into
the one source file that could no longer see a declaration of
'innermost_block'.

gdb/ChangeLog:

	* expression.h (innermost_block): Remove declaration.
	* varobj.c: Add 'parser-defs.h' include.

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2018-01-21  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* expression.h (innermost_block): Remove declaration.
+	* varobj.c: Add 'parser-defs.h' include.
+
 2018-01-19  Tom Tromey  <tom@tromey.com>
 
 	* rust-lang.c (rust_lookup_symbol_nonlocal): Look up qualified

gdb/expression.h

@@ -111,11 +111,6 @@ extern expression_up parse_exp_1 (const char **, CORE_ADDR pc,
    attempt completion.  */
 extern int parse_completion;
 
-/* The innermost context required by the stack and register variables
-   we've encountered so far.  To use this, set it to NULL, then call
-   parse_<whatever>, then look at it.  */
-extern const struct block *innermost_block;
-
 /* From eval.c */
 
 /* Values of NOSIDE argument to eval_subexp.  */

gdb/varobj.c

@@ -30,6 +30,7 @@
 #include "gdbthread.h"
 #include "inferior.h"
 #include "varobj-iter.h"
+#include "parser-defs.h"
 
 #if HAVE_PYTHON
 #include "python/python.h"