compiler: add complex manipulation

* builtins: real, imag, complex
* printing of complex numbers

No support for complex arithmetic yet.

testdata/float.go

@@ -23,4 +23,24 @@ func main() {
 	// casting
 	println(float32(f64))
 	println(float64(f32))
+
+	// complex64
+	c64 := complex(f32, 1.2)
+	println(c64)
+	println(real(c64))
+	println(imag(c64))
+
+	// complex128
+	c128 := complex(f64, -2.0)
+	println(c128)
+	println(real(c128))
+	println(imag(c128))
+
+	// untyped complex
+	println(2 + 1i)
+	println(complex(2, -2))
+
+	// cast complex
+	println(complex64(c128))
+	println(complex128(c64))
 }

testdata/float.txt

@@ -11,3 +11,13 @@
 +3.333333e-001
 +6.666667e-001
 +6.666667e-001
+(+6.666667e-001+1.200000e+000i)
++6.666667e-001
++1.200000e+000
+(+6.666667e-001-2.000000e+000i)
++6.666667e-001
+-2.000000e+000
+(+2.000000e+000+1.000000e+000i)
+(+2.000000e+000-2.000000e+000i)
+(+6.666667e-001-2.000000e+000i)
+(+6.666667e-001+1.200000e+000i)

testdata/print.go

@@ -29,6 +29,9 @@ func main() {
 	// print float64
 	println(3.14)
 
+	// print complex128
+	println(5+1.2345i)
+
 	// print interface
 	println(interface{}(nil))
 

testdata/print.txt

@@ -16,6 +16,7 @@ a b c
 123456789012
 -123456789012
 +3.140000e+000
+(+5.000000e+000+1.234500e+000i)
 (0:nil)
 map[2]
 true false