DOONBEG — Every time President Trump rails against big “pharma” over the jobs that have been shipped overseas, his pledges to streamline regulations and lower taxes to lure them home prompt grimaces 3,000 miles across the Atlantic Ocean. More than 50,000 people are employed with pharmaceutical and medical device companies here in Ireland, with most of the companies refugees from America. Baxter, a medical equipment manufacturer based in Deerfield, Illinois, employs a thousand people in Ireland. Pfizer, Boston Scientific and Johnson & Johnson all have substantial Irish operations. Dublin’s Silicon Docks neighborhood earned its nickname after Facebook, Google, Twitter and other U.S. tech companies set up in glossy offices, often mammoth European headquarters, close to the River Liffey. They are among an estimated 700 U.S. companies which, attracted by Ireland’s low corporate tax rate and English-speaking work force, have helped drive a multinational invasion on the Emerald Isle that once turned it into the “Celtic Tiger” of Europe, employing around 170,000 people in all.