Add default clang to ubuntu images

Author: gavv

images/env-ubuntu/16.04/Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update
 # compilers and tools
 RUN apt-get install -y \
     ccache \
+    clang \
     clang-3.5 \
     clang-3.6 \
     clang-3.7 \

images/env-ubuntu/18.04/Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update
 # compilers and tools
 RUN apt-get install -y \
     ccache \
+    clang \
     clang-3.9 \
     clang-4.0 \
     clang-5.0 \

images/env-ubuntu/20.04/Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update
 # compilers and tools
 RUN apt-get install -y \
     ccache \
+    clang \
     clang-6.0 \
     clang-7 \
     clang-8 \

images/env-ubuntu/22.04/Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update
 # compilers and tools
 RUN apt-get install -y \
     ccache \
+    clang \
     clang-11 \
     clang-12 \
     clang-13 \

images/env-ubuntu/24.04/Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update
 # compilers and tools
 RUN apt-get install -y \
     ccache \
+    clang \
     clang-14 \
     clang-15 \
     clang-16 \