Support multiple rsp files in REParams

rewrapper supports a comma separate list of rsp files, replace
REParams.RSPFile with REParmas.RSPFiles.

Test: remoteexec_test.go
Change-Id: I7850c071c23d368d6fad4480dd527d146c13c6d3
diff --git a/cc/builder.go b/cc/builder.go
index 273cdd3..4771b89 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -73,7 +73,7 @@
 			Labels:          map[string]string{"type": "link", "tool": "clang"},
 			ExecStrategy:    "${config.RECXXLinksExecStrategy}",
 			Inputs:          []string{"${out}.rsp", "$implicitInputs"},
-			RSPFile:         "${out}.rsp",
+			RSPFiles:        []string{"${out}.rsp"},
 			OutputFiles:     []string{"${out}", "$implicitOutputs"},
 			ToolchainInputs: []string{"$ldCmd"},
 			Platform:        map[string]string{remoteexec.PoolKey: "${config.RECXXLinksPool}"},
@@ -256,7 +256,7 @@
 			Labels:          map[string]string{"type": "tool", "name": "abi-linker"},
 			ExecStrategy:    "${config.REAbiLinkerExecStrategy}",
 			Inputs:          []string{"$sAbiLinkerLibs", "${out}.rsp", "$implicitInputs"},
-			RSPFile:         "${out}.rsp",
+			RSPFiles:        []string{"${out}.rsp"},
 			OutputFiles:     []string{"$out"},
 			ToolchainInputs: []string{"$sAbiLinker"},
 			Platform:        map[string]string{remoteexec.PoolKey: "${config.RECXXPool}"},