Fix alloc build

src/pe/header.rs

@@ -1,3 +1,4 @@
+use crate::alloc::vec::Vec;
 use crate::error;
 use crate::pe::{optional_header, section_table, symbol};
 use crate::strtab;

src/pe/section_table.rs

@@ -2,7 +2,6 @@ use crate::alloc::string::{String, ToString};
 use scroll::{ctx, Pread, Pwrite};
 use crate::error::{self, Error};
 use crate::pe::relocation;
-use std::io::Write;
 
 #[repr(C)]
 #[derive(Debug, PartialEq, Clone, Default)]
@@ -93,7 +92,25 @@ impl SectionTable {
         if idx <= 9_999_999 { // 10^7 - 1
             self.name = [0; 8];
             self.name[0] = b'/';
-            write!(&mut self.name[1..], "{}", idx).unwrap();
+            if idx == 0 {
+                self.name[1] = b'0';
+            } else {
+                let mut i = 0;
+                while idx != 0 {
+                    let rem = (idx % 10) as u8;
+                    idx /= 10;
+                    self.name[7 - i] = b'0' + rem;
+                    i += 1;
+                }
+                if i < 7 {
+                    for j in 0..i {
+                        self.name[1 + j] = self.name[8 - i + j]
+                    }
+                    for j in i..7 {
+                        self.name[1 + j] = 0;
+                    }
+                }
+            }
             Ok(())
         } else if idx as u64 <= 0xfff_fff_fff { // 64^6 - 1
             self.name[0] = b'/';

src/pe/symbol.rs

@@ -1,3 +1,4 @@
+use crate::alloc::vec::Vec;
 use crate::error;
 use crate::strtab;
 use core::fmt::{self, Debug};