Remove parser_state "initial_size" parameter

All the real (not test) uses of parser_state pass 10 as the
"initial_size" parameter, and it seems to me that there's no real
reason to require callers to set this.  This patch removes this
parameter.

gdb/ChangeLog
2019-04-04  Tom Tromey  <tom@tromey.com>

	* dtrace-probe.c (dtrace_probe::build_arg_exprs): Update.
	* stap-probe.c (stap_parse_argument): Update.
	* stap-probe.h (struct stap_parse_info) <stap_parse_info>: Remove
	initial_size parameter.
	* rust-exp.y (rust_lex_tests): Update.
	* parse.c (parser_state): Update.
	(parse_exp_in_context): Update.
	* parser-defs.h (struct parser_state) <parser_state>: Remove
	"initial_size" parameter.

gdb/ChangeLog

@@ -1,3 +1,15 @@
+2019-04-04  Tom Tromey  <tom@tromey.com>
+
+	* dtrace-probe.c (dtrace_probe::build_arg_exprs): Update.
+	* stap-probe.c (stap_parse_argument): Update.
+	* stap-probe.h (struct stap_parse_info) <stap_parse_info>: Remove
+	initial_size parameter.
+	* rust-exp.y (rust_lex_tests): Update.
+	* parse.c (parser_state): Update.
+	(parse_exp_in_context): Update.
+	* parser-defs.h (struct parser_state) <parser_state>: Remove
+	"initial_size" parameter.
+
 2019-04-04  Tom Tromey  <tom@tromey.com>
 
 	* parser-defs.h (increase_expout_size): Don't declare.

gdb/dtrace-probe.c

@@ -627,7 +627,7 @@ dtrace_probe::build_arg_exprs (struct gdbarch *gdbarch)
       /* Initialize the expression buffer in the parser state.  The
 	 language does not matter, since we are using our own
 	 parser.  */
-      parser_state pstate (10, current_language, gdbarch);
+      parser_state pstate (current_language, gdbarch);
 
       /* The argument value, which is ABI dependent and casted to
 	 `long int'.  */

gdb/parse.c

@@ -165,10 +165,9 @@ end_arglist (void)
 
 /* See definition in parser-defs.h.  */
 
-parser_state::parser_state (size_t initial_size,
-			    const struct language_defn *lang,
+parser_state::parser_state (const struct language_defn *lang,
 			    struct gdbarch *gdbarch)
-  : expout_size (initial_size),
+  : expout_size (10),
     expout (XNEWVAR (expression,
 		     (sizeof (expression)
 		      + EXP_ELEM_TO_BYTES (expout_size)))),
@@ -1190,7 +1189,7 @@ parse_exp_in_context (const char **stringptr, CORE_ADDR pc,
      and others called from *.y) ensure CURRENT_LANGUAGE gets restored
      to the value matching SELECTED_FRAME as set by get_current_arch.  */
 
-  parser_state ps (10, lang, get_current_arch ());
+  parser_state ps (lang, get_current_arch ());
 
   scoped_restore_current_language lang_saver;
   set_language (lang->la_language);

gdb/parser-defs.h

@@ -37,11 +37,10 @@ extern int parser_debug;
 
 struct parser_state
 {
-  /* Constructor.  INITIAL_SIZE is the initial size of the expout
-     array.  LANG is the language used to parse the expression.  And
-     GDBARCH is the gdbarch to use during parsing.  */
+  /* Constructor.  LANG is the language used to parse the expression.
+     And GDBARCH is the gdbarch to use during parsing.  */
 
-  parser_state (size_t initial_size, const struct language_defn *lang,
+  parser_state (const struct language_defn *lang,
 		struct gdbarch *gdbarch);
 
   DISABLE_COPY_AND_ASSIGN (parser_state);

gdb/rust-exp.y

@@ -2707,7 +2707,7 @@ rust_lex_tests (void)
   int i;
 
   // Set up dummy "parser", so that rust_type works.
-  struct parser_state ps (0, &rust_language_defn, target_gdbarch ());
+  struct parser_state ps (&rust_language_defn, target_gdbarch ());
   rust_parser parser (&ps);
 
   rust_lex_test_one (&parser, "", 0);

gdb/stap-probe.c

@@ -1149,7 +1149,7 @@ stap_parse_argument (const char **arg, struct type *atype,
   /* We need to initialize the expression buffer, in order to begin
      our parsing efforts.  We use language_c here because we may need
      to do pointer arithmetics.  */
-  struct stap_parse_info p (*arg, atype, 10, language_def (language_c),
+  struct stap_parse_info p (*arg, atype, language_def (language_c),
 			    gdbarch);
 
   stap_parse_argument_1 (&p, 0, STAP_OPERAND_PREC_NONE);

gdb/stap-probe.h

@@ -29,10 +29,10 @@
 struct stap_parse_info
 {
   stap_parse_info (const char *arg_, struct type *arg_type_,
-		   size_t initial_size, const struct language_defn *lang,
+		   const struct language_defn *lang,
 		   struct gdbarch *gdbarch)
     : arg (arg_),
-      pstate (initial_size, lang, gdbarch),
+      pstate (lang, gdbarch),
       saved_arg (arg_),
       arg_type (arg_type_),
       gdbarch (gdbarch),