Delay definition of pc_moved_p

to unify the duplicated declarations and to make sure it's not used
until set properly.

Also changed it from legacy TRUE/FALSE to stdbool.

tool/ruby_vm/views/_mjit_compile_insn.erb

@@ -7,7 +7,6 @@
 % # details.
     fprintf(f, "{\n");
     {
-        MAYBE_UNUSED(int pc_moved_p) = FALSE;
 % # compiler: Prepare operands which may be used by `insn.call_attribute`
 % insn.opes.each_with_index do |ope, i|
         MAYBE_UNUSED(<%= ope.fetch(:decl) %>) = (<%= ope.fetch(:type) %>)operands[<%= i %>];

tool/ruby_vm/views/_mjit_compile_pc_and_sp.erb

@@ -6,9 +6,10 @@
 % # details.
 %
 % # JIT: Move pc for catch table on catch_except_p, and for #caller_locations and rb_profile_frames on !insn.always_leaf?
+        MAYBE_UNUSED(bool pc_moved_p) = false;
         if (body->catch_except_p || <%= insn.always_leaf? ? 'FALSE' : 'TRUE' %>) {
             fprintf(f, "    reg_cfp->pc = original_body_iseq + %d;\n", next_pos); /* ADD_PC(INSN_ATTR(width)); */
-            pc_moved_p = TRUE;
+            pc_moved_p = true;
         }
 %
 % # JIT: move sp to use or preserve stack variables

tool/ruby_vm/views/_mjit_compile_send.erb

@@ -8,7 +8,6 @@
 %
 % # Optimized case of send / opt_send_without_block instructions.
 {
-    MAYBE_UNUSED(int pc_moved_p) = FALSE;
 % # compiler: Prepare operands which may be used by `insn.call_attribute`
 % insn.opes.each_with_index do |ope, i|
     MAYBE_UNUSED(<%= ope.fetch(:decl) %>) = (<%= ope.fetch(:type) %>)operands[<%= i %>];