Add documentation for module resolution.
I found this in the CL description of
I5fda1a77f58814097b10b5ad2743ee25adfaecc4, and modified it slightly.
Bug: 111154853
Test: No
Change-Id: I984ac1a9521357af6b54340939dcde36988fc634
diff --git a/core/main.mk b/core/main.mk
index bc99284..0d2cc34 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -895,6 +895,14 @@
# The base list of modules to build for this product is specified
# by the appropriate product definition file, which was included
# by product_config.mk.
+# Name resolution for PRODUCT_PACKAGES:
+# foo:32 resolves to foo_32;
+# foo:64 resolves to foo;
+# foo resolves to both foo and foo_32 (if foo_32 is defined).
+#
+# Name resolution for LOCAL_REQUIRED_MODULES:
+# If a module is built for 2nd arch, its required module resolves to
+# 32-bit variant, if it exits. See the select-bitness-of-required-modules definition.
# $(1): product makefile
define product-installed-files
$(eval _pif_modules := $(PRODUCTS.$(strip $(1)).PRODUCT_PACKAGES)) \