[BOLT] Reject processing of PIE binaries

Summary:
Check if the input binary ELF type. Reject any binary not of
ET_EXEC type, including position-independent executables (PIEs).

Also print the first function containing PIC jump table.

(cherry picked from FBD8707274)

bolt/src/BinaryFunction.cpp

@@ -1407,7 +1407,7 @@ void BinaryFunction::postProcessJumpTables() {
     if (JT.Type == JumpTable::JTT_PIC && opts::JumpTables == JTS_BASIC) {
       opts::JumpTables = JTS_MOVE;
       outs() << "BOLT-INFO: forcing -jump-tables=move as PIC jump table was "
-                "detected\n";
+                "detected in function " << *this << '\n';
     }
     for (unsigned I = 0; I < JT.OffsetEntries.size(); ++I) {
       auto Offset = JT.OffsetEntries[I];

bolt/src/RewriteInstance.cpp

@@ -804,6 +804,11 @@ void RewriteInstance::discoverStorage() {
     exit(1);
   }
   auto Obj = ELF64LEFile->getELFFile();
+  if (Obj->getHeader()->e_type != ELF::ET_EXEC) {
+    errs() << "BOLT-ERROR: only non-PIE ELF executables are supported at the "
+              "moment.\n";
+    exit(1);
+  }
 
   EntryPoint = Obj->getHeader()->e_entry;