gollvm: fix up cmd/carchive tool test failure

The test directory of cmd/carchive tool contains two interdependent test files:
carchive_test.go and overlaydir_test.go, but the current test script only contains
carchive_test.go, which causes the test to fail. This change fixes this bug.

Change-Id: I3648f1b1459b33a94a73aa46d83898786b2f275c
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/209379
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/gotools/CMakeLists.txt b/gotools/CMakeLists.txt
index 06d7336..946f6f0 100644
--- a/gotools/CMakeLists.txt
+++ b/gotools/CMakeLists.txt
@@ -219,7 +219,7 @@
   VERBATIM)
 list(APPEND checktargets ${targetname})
 
-# Run `go test misc/cgo/testcarchive/carchive_test.go` in the build env.
+# Run `go test misc/cgo/testcarchive/*_test.go` in the build env.
 set(targetname "check_carchive_tool")
 add_custom_target(
   ${targetname}
@@ -231,7 +231,6 @@
     "TIMEOUT" ${default_check_timeout}
     "GOC" "${rungoc}"
     "CC" "${runcc}"
-    "TESTARG" "carchive_test.go"
     "BINDIR" ${gotools_binroot}
     "LIBDIR" ${libgo_binroot}
   DEPENDS ${libgo_goxfiles} libgotool libgo_shared gotools_all libgobegin libgolibbegin