bp2build support for host_ldlibs

host_ldlibs are used during linking. Set these in `linkopts` for now.

Note that this CL does not do the `CheckBadHostLdLibs` validation of
Soong. There are some different ways to do this, and these are being
discussed in b/216626461. It is likely that we will need to create a new
property `host_ldlibs` to do the validation. But for now, re-use
`linkopts`.

Bug: 216626461
Test: bp2build unit tests
Change-Id: Id4c77e4460fb1fb003fa58ea27bab5b50ea8cefe
diff --git a/bp2build/cc_library_conversion_test.go b/bp2build/cc_library_conversion_test.go
index 17b1608..7cccec1 100644
--- a/bp2build/cc_library_conversion_test.go
+++ b/bp2build/cc_library_conversion_test.go
@@ -4657,3 +4657,49 @@
 		},
 	})
 }
+
+func TestCcLibraryHostLdLibs(t *testing.T) {
+	runCcLibraryTestCase(t, Bp2buildTestCase{
+		Description:                "cc_binary linker flags for host_ldlibs",
+		ModuleTypeUnderTest:        "cc_binary",
+		ModuleTypeUnderTestFactory: cc.BinaryFactory,
+		Blueprint: soongCcLibraryPreamble + `cc_binary {
+    name: "a",
+    host_supported: true,
+    ldflags: ["-lcommon"],
+    target: {
+	linux: {
+		host_ldlibs: [
+			"-llinux",
+		],
+	},
+	darwin: {
+		ldflags: ["-ldarwinadditional"],
+		host_ldlibs: [
+			"-ldarwin",
+		],
+	},
+	windows: {
+		host_ldlibs: [
+			"-lwindows",
+		],
+	},
+    },
+}
+`,
+		ExpectedBazelTargets: []string{
+			MakeBazelTargetNoRestrictions("cc_binary", "a", AttrNameToString{
+				"linkopts": `["-lcommon"] + select({
+        "//build/bazel/platforms/os:darwin": [
+            "-ldarwinadditional",
+            "-ldarwin",
+        ],
+        "//build/bazel/platforms/os:linux_glibc": ["-llinux"],
+        "//build/bazel/platforms/os:windows": ["-lwindows"],
+        "//conditions:default": [],
+    })`,
+				"local_includes": `["."]`,
+			}),
+		},
+	})
+}