Add scalar lowering for sqrt intrinsic.

crosstest/runtests.sh

 #!/bin/sh
 
 # TODO: Retire this script and move the individual tests into the lit
 # framework, to leverage parallel testing and other lit goodness.
 
 set -eux
 
 OPTLEVELS="m1 2"
 OUTDIR=Output
 # Clean the output directory to avoid reusing stale results.
@@ skipping 12 matching lines @@
     ./crosstest.py -O${optlevel} --prefix=Subzero_ --target=x8632 \
         --dir="${OUTDIR}" \
         --llvm-bin-path="${LLVM_BIN_PATH}" \
         --test=mem_intrin.cpp \
         --driver=mem_intrin_main.cpp \
         --output=mem_intrin_O${optlevel}
 
     ./crosstest.py -O${optlevel} --prefix=Subzero_ --target=x8632 \
         --dir="${OUTDIR}" \
         --llvm-bin-path="${LLVM_BIN_PATH}" \
-        --test=test_arith.cpp --test=test_arith_frem.ll \
+        --test=test_arith.cpp \
+        --test=test_arith_frem.ll \
+        --test=test_arith_sqrt.ll \
         --driver=test_arith_main.cpp \
         --output=test_arith_O${optlevel}
 
     ./crosstest.py -O${optlevel} --prefix=Subzero_ --target=x8632 \
         --dir="${OUTDIR}" \
         --llvm-bin-path="${LLVM_BIN_PATH}" \
         --test=test_cast.cpp --test=test_cast_to_u1.ll \
         --driver=test_cast_main.cpp \
         --output=test_cast_O${optlevel}
 
@@ skipping 22 matching lines @@
 
 for optlevel in ${OPTLEVELS} ; do
     "${OUTDIR}"/simple_loop_O${optlevel}
     "${OUTDIR}"/mem_intrin_O${optlevel}
     "${OUTDIR}"/test_arith_O${optlevel}
     "${OUTDIR}"/test_cast_O${optlevel}
     "${OUTDIR}"/test_fcmp_O${optlevel}
     "${OUTDIR}"/test_global_O${optlevel}
     "${OUTDIR}"/test_icmp_O${optlevel}
 done