LLVM: Add ELF Note section to NaCl object files identifying them as such to gold

test/MC/Mips/elf-note-nacl.ll

Index: test/MC/Mips/elf-note-nacl.ll
diff --git a/test/MC/Mips/elf-note-nacl.ll b/test/MC/Mips/elf-note-nacl.ll
new file mode 100644
index 0000000000000000000000000000000000000000..0361eff25e29de4676585550cd1bd5bba1812a0a
--- /dev/null
+++ b/test/MC/Mips/elf-note-nacl.ll
@@ -0,0 +1,22 @@
+; RUN: llc -filetype=obj -mtriple mipsel-none-nacl %s -o - \
+; RUN:   | llvm-objdump -triple mipsel -s - | FileCheck %s
+
+; Tests that NaCl object files contain an ELF note section that identifies them
+; to the binutils gold linker
+
+define void @main() {
+  ret void
+}
+
+; There appears to be no way for llvm-objdump to show flags for sections, or
+; to dump groups like readelf.
+; CHECK: .group
+; CHECK: .note.NaCl.ABI.mipsel
+; The contents of the words in the note section should be:
+;   sizeof "NaCl"
+;   sizeof "mipsel"
+;   1 (NT_VERSION)
+;   "NaCl" with nul termination and padding to align 4
+;   "mipsel" with nul termination and padding to align 4
+; CHECK-NEXT: 0000 05000000 07000000 01000000 4e61436c
+; CHECK-NEXT: 0010 00000000 6d697073 656c0000