Support Rust in Ramdisk

Bug: 178565008
Bug: 165791368
Test: Build and link a Rust library into a ramdisk binary
Change-Id: I9682b978936624133e5a62e94caace0e8958fd0f
diff --git a/rust/rust.go b/rust/rust.go
index 70721fb..ba395ec 100644
--- a/rust/rust.go
+++ b/rust/rust.go
@@ -84,6 +84,7 @@
 	// Set by imageMutator
 	CoreVariantNeeded          bool     `blueprint:"mutated"`
 	VendorRamdiskVariantNeeded bool     `blueprint:"mutated"`
+	RamdiskVariantNeeded       bool     `blueprint:"mutated"`
 	RecoveryVariantNeeded      bool     `blueprint:"mutated"`
 	ExtraVariants              []string `blueprint:"mutated"`
 
@@ -95,6 +96,13 @@
 	SnapshotSharedLibs []string `blueprint:"mutated"`
 	SnapshotStaticLibs []string `blueprint:"mutated"`
 
+	// Make this module available when building for ramdisk.
+	// On device without a dedicated recovery partition, the module is only
+	// available after switching root into
+	// /first_stage_ramdisk. To expose the module before switching root, install
+	// the recovery variant instead.
+	Ramdisk_available *bool
+
 	// Make this module available when building for vendor ramdisk.
 	// On device without a dedicated recovery partition, the module is only
 	// available after switching root into
@@ -817,6 +825,8 @@
 		} else {
 			mod.Properties.SubName += cc.VendorSuffix
 		}
+	} else if mod.InRamdisk() && !mod.OnlyInRamdisk() {
+		mod.Properties.SubName += cc.RamdiskSuffix
 	} else if mod.InVendorRamdisk() && !mod.OnlyInVendorRamdisk() {
 		mod.Properties.SubName += cc.VendorRamdiskSuffix
 	} else if mod.InRecovery() && !mod.OnlyInRecovery() {