patch 9.0.1594: some internal error messages are translated

Problem:    Some internal error messages are translated.
Solution:   Consistently do not translate internal error messages.
            (closes #12459)
diff --git a/src/memline.c b/src/memline.c
index 40cb010..46e7d8a 100644
--- a/src/memline.c
+++ b/src/memline.c
@@ -332,7 +332,7 @@
 	goto error;
     if (hp->bh_bnum != 0)
     {
-	iemsg(_(e_didnt_get_block_nr_zero));
+	iemsg(e_didnt_get_block_nr_zero);
 	goto error;
     }
     b0p = (ZERO_BL *)(hp->bh_data);
@@ -382,7 +382,7 @@
 	goto error;
     if (hp->bh_bnum != 1)
     {
-	iemsg(_(e_didnt_get_block_nr_one));
+	iemsg(e_didnt_get_block_nr_one);
 	goto error;
     }
     pp = (PTR_BL *)(hp->bh_data);
@@ -400,7 +400,7 @@
 	goto error;
     if (hp->bh_bnum != 2)
     {
-	iemsg(_(e_didnt_get_block_nr_two));
+	iemsg(e_didnt_get_block_nr_two);
 	goto error;
     }
 
@@ -974,7 +974,7 @@
 
     b0p = (ZERO_BL *)(hp->bh_data);
     if (ml_check_b0_id(b0p) == FAIL)
-	iemsg(_(e_ml_upd_block0_didnt_get_block_zero));
+	iemsg(e_ml_upd_block0_didnt_get_block_zero);
     else
     {
 	if (what == UB_FNAME)
@@ -2678,7 +2678,7 @@
 	    // Avoid giving this message for a recursive call, may happen when
 	    // the GUI redraws part of the text.
 	    ++recursive;
-	    siemsg(_(e_ml_get_invalid_lnum_nr), lnum);
+	    siemsg(e_ml_get_invalid_lnum_nr, lnum);
 	    --recursive;
 	}
 	ml_flush_line(buf);
@@ -2725,7 +2725,7 @@
 		++recursive;
 		get_trans_bufname(buf);
 		shorten_dir(NameBuff);
-		siemsg(_(e_ml_get_cannot_find_line_nr_in_buffer_nr_str),
+		siemsg(e_ml_get_cannot_find_line_nr_in_buffer_nr_str,
 						  lnum, buf->b_fnum, NameBuff);
 		--recursive;
 	    }
@@ -3219,7 +3219,7 @@
 	    pp = (PTR_BL *)(hp->bh_data);   // must be pointer block
 	    if (pp->pb_id != PTR_ID)
 	    {
-		iemsg(_(e_pointer_block_id_wrong_three));
+		iemsg(e_pointer_block_id_wrong_three);
 		mf_put(mfp, hp, FALSE, FALSE);
 		goto theend;
 	    }
@@ -3360,7 +3360,7 @@
 	 */
 	if (stack_idx < 0)
 	{
-	    iemsg(_(e_updated_too_many_blocks));
+	    iemsg(e_updated_too_many_blocks);
 	    buf->b_ml.ml_stack_top = 0;	// invalidate stack
 	}
     }
@@ -3820,7 +3820,7 @@
 	    pp = (PTR_BL *)(hp->bh_data);   // must be pointer block
 	    if (pp->pb_id != PTR_ID)
 	    {
-		iemsg(_(e_pointer_block_id_wrong_four));
+		iemsg(e_pointer_block_id_wrong_four);
 		mf_put(mfp, hp, FALSE, FALSE);
 		goto theend;
 	    }
@@ -4085,7 +4085,7 @@
 
 	hp = ml_find_line(buf, lnum, ML_FIND);
 	if (hp == NULL)
-	    siemsg(_(e_cannot_find_line_nr), lnum);
+	    siemsg(e_cannot_find_line_nr, lnum);
 	else
 	{
 	    dp = (DATA_BL *)(hp->bh_data);
@@ -4345,7 +4345,7 @@
 	pp = (PTR_BL *)(dp);		// must be pointer block
 	if (pp->pb_id != PTR_ID)
 	{
-	    iemsg(_(e_pointer_block_id_wrong));
+	    iemsg(e_pointer_block_id_wrong);
 	    goto error_block;
 	}
 
@@ -4390,11 +4390,11 @@
 	if (idx >= (int)pp->pb_count)	    // past the end: something wrong!
 	{
 	    if (lnum > buf->b_ml.ml_line_count)
-		siemsg(_(e_line_number_out_of_range_nr_past_the_end),
+		siemsg(e_line_number_out_of_range_nr_past_the_end,
 					      lnum - buf->b_ml.ml_line_count);
 
 	    else
-		siemsg(_(e_line_count_wrong_in_block_nr), bnum);
+		siemsg(e_line_count_wrong_in_block_nr, bnum);
 	    goto error_block;
 	}
 	if (action == ML_DELETE)
@@ -4487,7 +4487,7 @@
 	if (pp->pb_id != PTR_ID)
 	{
 	    mf_put(mfp, hp, FALSE, FALSE);
-	    iemsg(_(e_pointer_block_id_wrong_two));
+	    iemsg(e_pointer_block_id_wrong_two);
 	    break;
 	}
 	pp->pb_pointer[ip->ip_index].pe_line_count += count;