Merge pull request #18751 from clnperez/update-gcc-to-5.3

Update gcc to 5.3

Dockerfile.gccgo

@@ -6,7 +6,7 @@
 # docker build -t docker -f Dockerfile.gccgo .
 #
 
-FROM gcc:5.2
+FROM gcc:5.3
 
 # Packaged dependencies
 RUN apt-get update && apt-get install -y \

Dockerfile.ppc64le

@@ -6,7 +6,7 @@
 # docker build -t docker -f Dockerfile.ppc64le .
 #
 
-FROM ppc64le/gcc:5.2
+FROM ppc64le/gcc:5.3
 
 # Packaged dependencies
 RUN apt-get update && apt-get install -y \