Add a test for constant folding of bitcast to/from floating point.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32446 91177308-0d34-0410-b5e6-96231b3b80d8

test/Feature/fold-fpcast.ll

@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | llvm-dis | not grep bitcast
+
+int %test1() {
+   ret int bitcast(float 3.7 to int)
+}
+
+float %test2() {
+  ret float bitcast(int 17 to float)
+}
+
+long %test3() {
+  ret long bitcast (double 3.1415926 to long)
+}
+
+double %test4() {
+  ret double bitcast (long 42 to double)
+}
+