Add support for sanitizer property

Add a new feature to cc modules that adds the cflags and libraries
necessary to implement AddressSanitizer, ThreadSanitizer, and
UndefinedBehaviorSanitizer.

Change-Id: Ibe5ffadc7ece56080a2521f2c7c00da9ef712584
diff --git a/cc/toolchain.go b/cc/toolchain.go
index 397ec09..09dcff2 100644
--- a/cc/toolchain.go
+++ b/cc/toolchain.go
@@ -74,6 +74,8 @@
 
 	SystemCppCppflags() string
 	SystemCppLdflags() string
+
+	AddressSanitizerRuntimeLibrary() string
 }
 
 type toolchainBase struct {
@@ -133,6 +135,10 @@
 	return ""
 }
 
+func (toolchainBase) AddressSanitizerRuntimeLibrary() string {
+	return ""
+}
+
 type toolchain64Bit struct {
 	toolchainBase
 }