[Courgette] Add third party-library: libdivsufsort.

courgette/BUILD.gn

Index: courgette/BUILD.gn
diff --git a/courgette/BUILD.gn b/courgette/BUILD.gn
index 8a9eeaf073b44e6b10388da47efa0e61ba92b525..08ac22abcb40434a7ae714101fc2b0c6c923a205 100644
--- a/courgette/BUILD.gn
+++ b/courgette/BUILD.gn
@@ -63,6 +63,11 @@ static_library("courgette_lib") {
     "third_party/bsdiff/bsdiff_search.h",
     "third_party/bsdiff/paged_array.h",
     "third_party/bsdiff/qsufsort.h",
+    "third_party/divsufsort/divsufsort.cc",
+    "third_party/divsufsort/divsufsort.h",
+    "third_party/divsufsort/divsufsort_private.h",
+    "third_party/divsufsort/sssort.cc",
+    "third_party/divsufsort/trsort.cc",
     "types_elf.h",
     "types_win_pe.h",
   ]
@@ -133,6 +138,7 @@ test("courgette_unittests") {
     "third_party/bsdiff/bsdiff_search_unittest.cc",
     "third_party/bsdiff/paged_array_unittest.cc",
     "third_party/bsdiff/qsufsort_unittest.cc",
+    "third_party/divsufsort/divsufsort_unittest.cc",
     "typedrva_unittest.cc",
     "versioning_unittest.cc",
   ]