Added support for ARM_REL32 and GOT_PREL

These changes add support for the R_ARM_REL32 type and R_ARM_GOT_PREL.  They are required to provide JIT support to Swift which in turn supports interpret mode.

Author: hpux735

lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp

@@ -480,6 +480,9 @@ void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
     *TargetPtr |= Value & 0xFFF;
     *TargetPtr |= ((Value >> 12) & 0xF) << 16;
     break;
+  case ELF::R_ARM_REL32:
+    *TargetPtr += Value - FinalAddress;
+    break;
     // Write 24 bit relative value to the branch instruction.
   case ELF::R_ARM_PC24: // Fall through.
   case ELF::R_ARM_CALL: // Fall through.
@@ -1324,6 +1327,19 @@ relocation_iterator RuntimeDyldELF::processRelocationRef(
                           RelType, 0);
         Section.advanceStubOffset(getMaxStubSize());
       }
+    } else if (RelType == ELF::R_ARM_GOT_PREL) {
+      uint32_t GOTOffset = allocateGOTEntries(SectionID, 1);
+
+      RelocationEntry GOTRE(SectionID, Offset, ELF::R_ARM_REL32, GOTOffset);
+      addRelocationForSection(GOTRE, GOTSectionID);
+
+      // Fill in the value of the symbol we're targeting into the GOT
+      RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset,
+                                              Value.Offset, ELF::R_ARM_ABS32);
+      if (Value.SymbolName)
+        addRelocationForSymbol(RE, Value.SymbolName);
+      else
+        addRelocationForSection(RE, Value.SectionID);
     } else {
       uint32_t *Placeholder =
         reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));