hypervisor: Implement getter/setter for StandardRegisters

This would be used to abstract away differences in KVM/MSHV
representation of StandardRegisters.

Signed-off-by: Jinank Jain <jinankjain@microsoft.com>

Cargo.lock

@@ -456,6 +456,16 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3fd119d74b830634cea2a0f58bbd0d54540518a14397557951e79340abc28c0"
 
+[[package]]
+name = "concat-idents"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f76990911f2267d837d9d0ad060aa63aaad170af40904b29461734c339030d4d"
+dependencies = [
+ "quote",
+ "syn 2.0.66",
+]
+
 [[package]]
 name = "concurrent-queue"
 version = "2.5.0"
@@ -982,6 +992,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "byteorder",
+ "concat-idents",
  "env_logger",
  "iced-x86",
  "igvm",