Split local and global cflags

Native compiler flags are currently applied in approximately:
global cflags
local cflags
local include dirs
global include dirs
global conlyflags
local conlyflags
global cppflags
local cppflags

This means that a flag that is enabled in the global cppflags
cannot be disabled in the local cflags, and an Android.bp author
must know to disable it in the local cppflags.  A better order
would be:
global cflags
global conlyflags
global cppflags
local cflags
local conlyflags
local cppflags
local include dirs
global include dirs

We are mixing both the global and local cflags into a single
variable, and similar for conlyflags and cppflags, which
prevents reordering them.  This CL prepares to reorder them
by splitting the global and local cflags into separate variables.

Bug: 143713277
Test: m native
Change-Id: Ic55a8c3516c331dc5f2af9d00e59ceca9d3e6c15
diff --git a/cc/test.go b/cc/test.go
index 5c49d6e..05e6fe5 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -220,20 +220,20 @@
 		return flags
 	}
 
-	flags.CFlags = append(flags.CFlags, "-DGTEST_HAS_STD_STRING")
+	flags.Local.CFlags = append(flags.Local.CFlags, "-DGTEST_HAS_STD_STRING")
 	if ctx.Host() {
-		flags.CFlags = append(flags.CFlags, "-O0", "-g")
+		flags.Local.CFlags = append(flags.Local.CFlags, "-O0", "-g")
 
 		switch ctx.Os() {
 		case android.Windows:
-			flags.CFlags = append(flags.CFlags, "-DGTEST_OS_WINDOWS")
+			flags.Local.CFlags = append(flags.Local.CFlags, "-DGTEST_OS_WINDOWS")
 		case android.Linux:
-			flags.CFlags = append(flags.CFlags, "-DGTEST_OS_LINUX")
+			flags.Local.CFlags = append(flags.Local.CFlags, "-DGTEST_OS_LINUX")
 		case android.Darwin:
-			flags.CFlags = append(flags.CFlags, "-DGTEST_OS_MAC")
+			flags.Local.CFlags = append(flags.Local.CFlags, "-DGTEST_OS_MAC")
 		}
 	} else {
-		flags.CFlags = append(flags.CFlags, "-DGTEST_OS_LINUX_ANDROID")
+		flags.Local.CFlags = append(flags.Local.CFlags, "-DGTEST_OS_LINUX_ANDROID")
 	}
 
 	return flags