[llvm-tapi] initial commit, supports ELF text stubs

http://lists.llvm.org/pipermail/llvm-dev/2018-September/126472.html

TextAPI is a library and accompanying tool that allows conversion between binary shared object stubs and textual counterparts. The motivations and uses cases for this are explained thoroughly in the llvm-dev proposal [1]. This initial commit proposes a potential structure for the TAPI library, also including support for reading/writing text-based ELF stubs (.tbe) in addition to preliminary support for reading binary ELF files. The goal for this patch is to ensure the project architecture appropriately welcomes integration of Mach-O stubbing from Apple's TAPI [2].

Added:

 - TextAPI library
 - .tbe read support
 - .tbe write (to raw_ostream) support

[1] http://lists.llvm.org/pipermail/llvm-dev/2018-September/126472.html
[2] https://github.com/ributzka/tapi

Differential Revision: https://reviews.llvm.org/D53051

llvm-svn: 348170
diff --git a/llvm/lib/TextAPI/ELF/ELFStub.cpp b/llvm/lib/TextAPI/ELF/ELFStub.cpp
new file mode 100644
index 0000000..248a078
--- /dev/null
+++ b/llvm/lib/TextAPI/ELF/ELFStub.cpp
@@ -0,0 +1,29 @@
+//===- ELFStub.cpp --------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===-----------------------------------------------------------------------===/
+
+#include "llvm/TextAPI/ELF/ELFStub.h"
+
+using namespace llvm;
+using namespace llvm::elfabi;
+
+ELFStub::ELFStub(ELFStub const &Stub) {
+  TbeVersion = Stub.TbeVersion;
+  Arch = Stub.Arch;
+  SoName = Stub.SoName;
+  NeededLibs = Stub.NeededLibs;
+  Symbols = Stub.Symbols;
+}
+
+ELFStub::ELFStub(ELFStub &&Stub) {
+  TbeVersion = std::move(Stub.TbeVersion);
+  Arch = std::move(Stub.Arch);
+  SoName = std::move(Stub.SoName);
+  NeededLibs = std::move(Stub.NeededLibs);
+  Symbols = std::move(Stub.Symbols);
+}