[ELF] Handle R_ARM_MOVT_PREL and R_ARM_PREL31 as non-address-taking r…

…elocations

This is an attempt to fix #545 though
I don't know if this is a correct fix.

elf/arch-arm32.cc

@@ -427,7 +427,7 @@ void InputSection<E>::scan_relocations(Context<E> &ctx) {
     case R_ARM_PREL31: {
       Action table[][4] = {
         // Absolute  Local    Imported data  Imported code
-        {  ERROR,    NONE,    ERROR,         ERROR },      // DSO
+        {  ERROR,    NONE,    ERROR,         PLT   },      // DSO
         {  ERROR,    NONE,    COPYREL,       PLT   },      // PIE
         {  NONE,     NONE,    COPYREL,       PLT   },      // PDE
       };