[WebAssembly] Add llvm-objdump support for wasm file format

This is the first part of an effort to add wasm binary
support across all llvm tools.

Patch by Sam Clegg

Differential Revision: https://reviews.llvm.org/D26172

llvm-svn: 288251
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.h b/llvm/tools/llvm-objdump/llvm-objdump.h
index c87ef2d..dace82a 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.h
+++ b/llvm/tools/llvm-objdump/llvm-objdump.h
@@ -79,6 +79,7 @@
 void printCOFFSymbolTable(const object::COFFObjectFile *o);
 void printMachOFileHeader(const object::ObjectFile *o);
 void printMachOLoadCommands(const object::ObjectFile *o);
+void printWasmFileHeader(const object::ObjectFile *o);
 void printExportsTrie(const object::ObjectFile *o);
 void printRebaseTable(const object::ObjectFile *o);
 void printBindTable(const object::ObjectFile *o);