gollvm: cmake changes for gofrontend CL 504415

Update cmake rules to mirror a libgo makefile change
related to mmap invocation.

Change-Id: Idbd55f33301fc05faf3a42502ef66e06b4bcc269
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/504539
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
diff --git a/bridge/go-system.h b/bridge/go-system.h
index c802d76..ade1d2d 100644
--- a/bridge/go-system.h
+++ b/bridge/go-system.h
@@ -80,4 +80,6 @@
 
 #define MAX(X,Y) ((X) > (Y) ? (X) : (Y))
 
+#define ATTRIBUTE_UNUSED __attribute__((__unused__))
+
 #endif // !defined(GO_SYSTEM_H)
diff --git a/libgo/CMakeLists.txt b/libgo/CMakeLists.txt
index 6fcdff6..7bf3a90 100644
--- a/libgo/CMakeLists.txt
+++ b/libgo/CMakeLists.txt
@@ -465,6 +465,7 @@
 # Base C files from the runtime dir.
 set(runtimecfiles
   "runtime/aeshash.c"
+  "runtime/env_posix.c"
   "runtime/go-assert.c"
   "runtime/go-caller.c"
   "runtime/go-callers.c"
@@ -476,9 +477,10 @@
   "runtime/go-memclr.c"
   "runtime/go-memequal.c"
   "runtime/go-memmove.c"
+  "runtime/go-mmap.c"
   "runtime/go-nanotime.c"
-  "runtime/go-now.c"
   "runtime/go-nosys.c"
+  "runtime/go-now.c"
   "runtime/go-reflect-call.c"
   "runtime/go-setenv.c"
   "runtime/go-signal.c"
@@ -487,7 +489,6 @@
   "runtime/go-unsetenv.c"
   "runtime/go-unwind.c"
   "runtime/go-varargs.c"
-  "runtime/env_posix.c"
   "runtime/panic.c"
   "runtime/print.c"
   "runtime/proc.c"