If the same file is specified more than once as an input file,
llvm-lib should ignore all but the first occurrence of the file.

RUN: rm -rf %t
RUN: mkdir -p %t

RUN: llvm-mc -triple=x86_64-pc-windows-msvc -filetype=obj -o %t/foo.o %S/Inputs/a.s
RUN: llvm-mc -triple=x86_64-pc-windows-msvc -filetype=obj -o %t/bar.o %S/Inputs/b.s
RUN: llvm-mc -triple=x86_64-pc-windows-msvc -filetype=obj -o %t/abc.o %S/Inputs/abc.s
RUN: llvm-lib -out:%t/foo.lib %t/foo.o %t/foo.o %t/abc.o %t/bar.o  %t/foo.o %t/foo.o

RUN: llvm-ar t %t/foo.lib | FileCheck %s
CHECK: bar.o
CHECK-NEXT: abc.o
CHECK-NEXT: foo.o
CHECK-NOT: foo.o

# Check that symbol map contains sorted, de-duplicated symbols.
RUN: cd %t && llvm-lib -out:foo.lib foo.o foo.o abc.o bar.o  foo.o foo.o
RUN: llvm-nm --print-armap %t/foo.lib | FileCheck %s --check-prefix=DUP
# DUP: Archive map
# DUP-NEXT: a in abc.o
# DUP-NEXT: b in bar.o
# DUP-NEXT: c in abc.o
# DUP-EMPTY