Finish <search.h>.

I'm unable to find a bug, but we've had requests for this internally
once or twice (though I pointed those folks at the STL), and there's
code we build for the host or in our bootloaders that would use this,
and there's reasonable-looking FreeBSD implementation ready and waiting.

Bug: N/A
Test: ran tests
Change-Id: I6ddee4b71bea4c22ed015debd31d3eaac4fcdd35
diff --git a/libc/Android.bp b/libc/Android.bp
index 204ad19..e7a2e09 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -218,6 +218,10 @@
         "upstream-freebsd/lib/libc/gen/sleep.c",
         "upstream-freebsd/lib/libc/gen/usleep.c",
         "upstream-freebsd/lib/libc/stdlib/getopt_long.c",
+        "upstream-freebsd/lib/libc/stdlib/hcreate.c",
+        "upstream-freebsd/lib/libc/stdlib/hcreate_r.c",
+        "upstream-freebsd/lib/libc/stdlib/hdestroy_r.c",
+        "upstream-freebsd/lib/libc/stdlib/hsearch_r.c",
         "upstream-freebsd/lib/libc/stdlib/qsort.c",
         "upstream-freebsd/lib/libc/stdlib/quick_exit.c",
         "upstream-freebsd/lib/libc/string/wcpcpy.c",
@@ -282,6 +286,7 @@
     cflags: [
         "-Wno-sign-compare",
         "-Wno-uninitialized",
+        "-Wno-unused-parameter",
         "-include freebsd-compat.h",
     ],