gdb/jit: return bool in jit_breakpoint_re_set_internal and jit_read_descriptor

This is a minor refactoring that converts the return type of
jit_read_descriptor and jit_breakpoint_re_set_internal functions
from 'int' to 'bool'.

The return value logic of jit_breakpoint_re_set_internal has been
reversed.  With this patch it now returns true if the jit breakpoint
has been successfully initialized.

gdb/ChangeLog:
2020-06-22  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* jit.c (jit_read_descriptor): Use bool as the return type.
	(jit_breakpoint_re_set_internal): Use bool as the return type.
	Invert the return value logic; return true if the jit breakpoint
	has been successfully initialized.
	(jit_inferior_init): Update the call to
	jit_breakpoint_re_set_internal.

gdb/ChangeLog

@@ -1,3 +1,12 @@
+2020-06-22  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>
+
+	* jit.c (jit_read_descriptor): Use bool as the return type.
+	(jit_breakpoint_re_set_internal): Use bool as the return type.
+	Invert the return value logic; return true if the jit breakpoint
+	has been successfully initialized.
+	(jit_inferior_init): Update the call to
+	jit_breakpoint_re_set_internal.
+
 2020-06-22  Pedro Alves  <palves@redhat.com>
 
 	PR gdb/25939

gdb/jit.c

@@ -329,9 +329,9 @@ get_jit_program_space_data ()
 }
 
 /* Helper function for reading the global JIT descriptor from remote
-   memory.  Returns 1 if all went well, 0 otherwise.  */
+   memory.  Returns true if all went well, false otherwise.  */
 
-static int
+static bool
 jit_read_descriptor (struct gdbarch *gdbarch,
 		     struct jit_descriptor *descriptor,
 		     struct jit_program_space_data *ps_data)
@@ -345,10 +345,10 @@ jit_read_descriptor (struct gdbarch *gdbarch,
   struct jit_objfile_data *objf_data;
 
   if (ps_data->objfile == NULL)
-    return 0;
+    return false;
   objf_data = get_jit_objfile_data (ps_data->objfile);
   if (objf_data->descriptor == NULL)
-    return 0;
+    return false;
 
   if (jit_debug)
     fprintf_unfiltered (gdb_stdlog,
@@ -370,7 +370,7 @@ jit_read_descriptor (struct gdbarch *gdbarch,
     {
       printf_unfiltered (_("Unable to read JIT descriptor from "
 			   "remote memory\n"));
-      return 0;
+      return false;
     }
 
   /* Fix the endianness to match the host.  */
@@ -381,7 +381,7 @@ jit_read_descriptor (struct gdbarch *gdbarch,
   descriptor->first_entry =
       extract_typed_address (&desc_buf[8 + ptr_size], ptr_type);
 
-  return 1;
+  return true;
 }
 
 /* Helper function for reading a JITed code entry from remote memory.  */
@@ -950,9 +950,9 @@ jit_breakpoint_deleted (struct breakpoint *b)
 }
 
 /* (Re-)Initialize the jit breakpoint if necessary.
-   Return 0 if the jit breakpoint has been successfully initialized.  */
+   Return true if the jit breakpoint has been successfully initialized.  */
 
-static int
+static bool
 jit_breakpoint_re_set_internal (struct gdbarch *gdbarch,
 				struct jit_program_space_data *ps_data)
 {
@@ -968,13 +968,13 @@ jit_breakpoint_re_set_internal (struct gdbarch *gdbarch,
       reg_symbol = lookup_bound_minimal_symbol (jit_break_name);
       if (reg_symbol.minsym == NULL
 	  || BMSYMBOL_VALUE_ADDRESS (reg_symbol) == 0)
-	return 1;
+	return false;
 
       desc_symbol = lookup_minimal_symbol (jit_descriptor_name, NULL,
 					   reg_symbol.objfile);
       if (desc_symbol.minsym == NULL
 	  || BMSYMBOL_VALUE_ADDRESS (desc_symbol) == 0)
-	return 1;
+	return false;
 
       objf_data = get_jit_objfile_data (reg_symbol.objfile);
       objf_data->register_code = reg_symbol.minsym;
@@ -994,7 +994,7 @@ jit_breakpoint_re_set_internal (struct gdbarch *gdbarch,
 			paddress (gdbarch, addr));
 
   if (ps_data->cached_code_address == addr)
-    return 0;
+    return true;
 
   /* Delete the old breakpoint.  */
   if (ps_data->jit_breakpoint != NULL)
@@ -1004,7 +1004,7 @@ jit_breakpoint_re_set_internal (struct gdbarch *gdbarch,
   ps_data->cached_code_address = addr;
   ps_data->jit_breakpoint = create_jit_event_breakpoint (gdbarch, addr);
 
-  return 0;
+  return true;
 }
 
 /* The private data passed around in the frame unwind callback
@@ -1252,7 +1252,7 @@ jit_inferior_init (struct gdbarch *gdbarch)
   jit_prepend_unwinder (gdbarch);
 
   ps_data = get_jit_program_space_data ();
-  if (jit_breakpoint_re_set_internal (gdbarch, ps_data) != 0)
+  if (!jit_breakpoint_re_set_internal (gdbarch, ps_data))
     return;
 
   /* Read the descriptor so we can check the version number and load