sim: Update gcc dependency

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/sim/Cargo.lock b/sim/Cargo.lock
index 9c43c4b..549a41e 100644
--- a/sim/Cargo.lock
+++ b/sim/Cargo.lock
@@ -5,7 +5,7 @@
  "docopt 0.6.86 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "gcc 0.3.38 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.15 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -39,7 +39,7 @@
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "gcc 0.3.38 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -87,7 +87,7 @@
 
 [[package]]
 name = "gcc"
-version = "0.3.38"
+version = "0.3.51"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -203,7 +203,7 @@
 "checksum docopt 0.6.86 (registry+https://github.com/rust-lang/crates.io-index)" = "4a7ef30445607f6fc8720f0a0a2c7442284b629cf0d049286860fae23e71c4d9"
 "checksum env_logger 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "15abd780e45b3ea4f76b4e9a26ff4843258dd8a3eed2775a0e7368c2e7936c2f"
 "checksum error-chain 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1cd681735364a04cd5d69f01a4f6768e70473941f8d86d8c224faf6955a75799"
-"checksum gcc 0.3.38 (registry+https://github.com/rust-lang/crates.io-index)" = "553f11439bdefe755bf366b264820f1da70f3aaf3924e594b886beb9c831bcf5"
+"checksum gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)" = "120d07f202dcc3f72859422563522b66fe6463a4c513df062874daad05f85f0a"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum lazy_static 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6abe0ee2e758cd6bc8a2cd56726359007748fbf4128da998b65d0b70f881e19b"
 "checksum libc 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)" = "044d1360593a78f5c8e5e710beccdc24ab71d1f01bc19a29bcacdba22e8475d8"