dockerfile: Add a new dockerfile for doing profiling

This goes on top of the regular Dockerfile or Dockerfile.dev.

Author: mstorsjo

Dockerfile.profile

@@ -0,0 +1,12 @@
+ARG BASE=mstorsjo/llvm-mingw:dev
+FROM $BASE
+
+COPY build-compiler-rt.sh build-llvm.sh ./
+RUN ./build-compiler-rt.sh --native $TOOLCHAIN_PREFIX
+
+RUN export PATH=$TOOLCHAIN_PREFIX/bin:$PATH && \
+    ./build-llvm.sh /tmp/dummy-prefix --disable-lldb --disable-clang-tools-extra --with-clang --disable-dylib --instrumented
+
+COPY pgo-training.sh pgo-training.make ./
+COPY test/ ./test/
+RUN ./pgo-training.sh llvm-project/llvm/build-instrumented $TOOLCHAIN_PREFIX