[build] use vendored version of ICU

scripts/vendor/icu.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+source "$(dirname "${BASH_SOURCE[0]}")/common.sh"
+
+NAME=icu
+VERSION=61.1
+ROOT=icu/source
+
+download "http://download.icu-project.org/files/icu4c/$VERSION/icu4c-${VERSION//./_}-src.tgz"
+init
+STRIP_COMPONENTS=2 extract_gzip "${ROOT}/common/*.h" "${ROOT}/common/*.cpp"
+STRIP_COMPONENTS=1 extract_gzip "icu/LICENSE"
+
+# List all files we want to extract
+FILES=(
+    ushape.cpp
+    ubidi.cpp
+    ubidi_props.cpp
+    ubidiln.cpp
+    ubidiwrt.cpp
+    ustring.cpp
+    uinvchar.cpp
+    uchar.cpp
+    udataswp.cpp
+    umath.cpp
+    utrie2.cpp
+    utf_impl.cpp
+    utypes.cpp
+    cmemory.cpp
+    cstring.cpp
+)
+
+# Find dependencies for all of these files
+echo ">> Finding dependencies..."
+ALL=()
+for FILE in "${FILES[@]}"; do 
+    ALL+=($(cd "common" && $CXX -std=c++14 -I. -c "$FILE" -M | sed -e 's/^[a-z0-9._-]*: *//;s/ *\\$//'))
+done
+
+# Remove duplicates
+IFS=$'\n' ALL=($(sort <<< "${ALL[*]}" | uniq | sed '/^\//d'))
+unset IFS
+
+echo ">> Copying files..."
+mkdir -p src include/unicode
+for FILE in "${ALL[@]}"; do
+    [[ "$FILE" = unicode/* ]] && DIR="include" || DIR="src"
+    # Copy file and replace #include "unicode/*" with #include <unicode/*> so that we can separate
+    # includes and source-only files.
+    sed 's/^#include \"\(unicode\/[^\"]\{1,\}\)\"/#include <\1>/' "common/$FILE" > "$DIR/$FILE"
+done
+
+rm -rf common
+
+file_list include src -name "*.h" -o -name "*.cpp"