Hunt down some small bugs

tool/decode/lib/asmcodegen.c

@@ -41,7 +41,7 @@ nodiscard char *tabpad(const char *s, unsigned width) {
   size_t i, l, need;
   l = strlen(s);
   need = width > l ? (roundup(width, 8) - l - 1) / 8 + 1 : 0;
-  p = memcpy(malloc(l + need + 1), s, l);
+  p = memcpy(malloc(l + need + 2), s, l);
   for (i = 0; i < need; ++i) p[l + i] = '\t';
   if (!need) {
     p[l] = ' ';

tool/decode/lib/elfidnames.c

@@ -221,6 +221,7 @@ const struct IdName kElfSpecialSectionNames[] = {
 };
 
 const struct IdName kElfNexgen32eRelocationNames[] = {
+    {R_X86_64_NONE, "NONE"},
     {R_X86_64_64, "64"},
     {R_X86_64_PC32, "PC32"},
     {R_X86_64_GOT32, "GOT32"},