Use zstd to compress debug info in cc libraries

We can save a significant amount of disk space by compressing
debug info in `lld` cc builds. This change configures a build
flag to instruct lld to compress debug info when building cc
libraries. Rather than adding a global config we add this to
each target individually to avoid linker failures on windows
cross build targets.

Test: m
Bug: 305277519

Change-Id: I4ab3d47fb0de7e31a39fb671cccde1acee3a2018
diff --git a/cc/config/x86_linux_bionic_host.go b/cc/config/x86_linux_bionic_host.go
index e006471..f80be99 100644
--- a/cc/config/x86_linux_bionic_host.go
+++ b/cc/config/x86_linux_bionic_host.go
@@ -53,6 +53,10 @@
 		"--gcc-toolchain=${LinuxBionicGccRoot}",
 	}
 
+	linuxBionicLldflags = append(linuxBionicLdflags,
+		"-Wl,--compress-debug-sections=zstd",
+	)
+
 	// Embed the linker into host bionic binaries. This is needed to support host bionic,
 	// as the linux kernel requires that the ELF interpreter referenced by PT_INTERP be
 	// either an absolute path, or relative from CWD. To work around this, we extract
@@ -71,7 +75,7 @@
 func init() {
 	exportedVars.ExportStringListStaticVariable("LinuxBionicCflags", linuxBionicCflags)
 	exportedVars.ExportStringListStaticVariable("LinuxBionicLdflags", linuxBionicLdflags)
-	exportedVars.ExportStringListStaticVariable("LinuxBionicLldflags", linuxBionicLdflags)
+	exportedVars.ExportStringListStaticVariable("LinuxBionicLldflags", linuxBionicLldflags)
 
 	// Use the device gcc toolchain for now
 	exportedVars.ExportStringStaticVariable("LinuxBionicGccVersion", x86_64GccVersion)