Thread Expected<...> up from libObject’s getType() for symbols to allow llvm-objdump to produce a good error message.

Produce another specific error message for a malformed Mach-O file when a symbol’s
section index is more than the number of sections.  The existing test case in test/Object/macho-invalid.test
for macho-invalid-section-index-getSectionRawName now reports the error with the message indicating
that a symbol at a specific index has a bad section index and that bad section index value.

Again converting interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. Where the existing code reported the error with a
string message or an error code it was converted to do the same.

Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values.  So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
"// TODO: Actually report errors helpfully" and a call something like
consumeError(NameOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.

llvm-svn: 268298
diff --git a/llvm/lib/Object/Object.cpp b/llvm/lib/Object/Object.cpp
index 58d8fa0..6777b32 100644
--- a/llvm/lib/Object/Object.cpp
+++ b/llvm/lib/Object/Object.cpp
@@ -101,9 +101,14 @@
 
 void LLVMMoveToContainingSection(LLVMSectionIteratorRef Sect,
                                  LLVMSymbolIteratorRef Sym) {
-  ErrorOr<section_iterator> SecOrErr = (*unwrap(Sym))->getSection();
-  if (std::error_code ec = SecOrErr.getError())
-    report_fatal_error(ec.message());
+  Expected<section_iterator> SecOrErr = (*unwrap(Sym))->getSection();
+  if (!SecOrErr) {
+   std::string Buf;
+   raw_string_ostream OS(Buf);
+   logAllUnhandledErrors(SecOrErr.takeError(), OS, "");
+   OS.flush();
+   report_fatal_error(Buf);
+  }
   *unwrap(Sect) = *SecOrErr;
 }