Merge pull request #3710 from diffblue/test-overflow-leftshift-c99

test signed left-shift overflow for C99

Author: Daniel Kroening

regression/cbmc/Overflow_Leftshift1/test-c99.desc

@@ -0,0 +1,16 @@
+CORE
+main.c
+--signed-overflow-check --c99
+^EXIT=10$
+^SIGNAL=0$
+^\[.*\] line 6 arithmetic overflow on signed shl in .*: FAILURE$
+^\[.*\] line 9 arithmetic overflow on signed shl in .*: SUCCESS$
+^\[.*\] line 15 arithmetic overflow on signed shl in .*: SUCCESS$
+^\[.*\] line 18 arithmetic overflow on signed shl in .*: FAILURE$
+^\[.*\] line 24 arithmetic overflow on signed shl in .*: FAILURE$
+^\*\* 3 of 6 failed
+^VERIFICATION FAILED$
+--
+^warning: ignoring
+^\[.*\] line 12 arithmetic overflow on signed shl in .*: .*
+^\[.*\] line 21 arithmetic overflow on signed shl in .*: .*