Enable safe ICF for all devices

--icf=safe has been enabled for arm and arm64.
Do the same thing for all devices.

On bertha_x86_64, this CL makes system.raw.img 4.4MB smaller.

Bug: 182446785
Test: build

Change-Id: Ifd597cd8496c49b55df269f22e01b1c50dc8f6e8

cc/config/arm64_device.go

@@ -46,7 +46,6 @@ var (
 	arm64Ldflags = []string{
 		"-Wl,--hash-style=gnu",
 		"-Wl,-z,separate-code",
-		"-Wl,--icf=safe",
 	}
 
 	arm64Lldflags = append(ClangFilterUnknownLldflags(arm64Ldflags),

cc/config/arm_device.go

@@ -34,7 +34,6 @@ var (
 	armCppflags = []string{}
 
 	armLdflags = []string{
-		"-Wl,--icf=safe",
 		"-Wl,--hash-style=gnu",
 		"-Wl,-m,armelf",
 	}

cc/config/global.go

@@ -97,6 +97,7 @@ var (
 		"-Wl,--exclude-libs,libgcc_stripped.a",
 		"-Wl,--exclude-libs,libunwind_llvm.a",
 		"-Wl,--exclude-libs,libunwind.a",
+		"-Wl,--icf=safe",
 	}
 
 	deviceGlobalLldflags = append(ClangFilterUnknownLldflags(deviceGlobalLdflags),