added typecheck for complex

Author: sampersand

test/typecheck/complex/Steepfile

@@ -0,0 +1,7 @@
+D = Steep::Diagnostic
+
+target :test do
+  signature "."
+  check "."
+  configure_code_diagnostics(D::Ruby.all_error)
+end

test/typecheck/complex/test.rb

@@ -0,0 +1,41 @@
+class Raises
+  def to_c = fail
+end
+
+class RaisesNumeric < Numeric
+  def to_c = fail
+end
+
+Complex(1) #: Complex
+Complex(1.23) #: Complex
+Complex(1r) #: Complex
+Complex(1i) #: Complex
+Complex(1ri) #: Complex
+Complex(Numeric.new) #: Complex
+Complex('1+2i') #: Complex
+
+Complex(1, exception: true) #: Complex
+Complex(1.23, exception: true) #: Complex
+Complex(1r, exception: true) #: Complex
+Complex(1i, exception: true) #: Complex
+Complex(1ri, exception: true) #: Complex
+Complex(Numeric.new, exception: true) #: Complex
+Complex("1+2i", exception: true) #: Complex
+
+Complex(Raises.new, exception: false) #: nil
+Complex(RaisesNumeric.new, exception: false) #: nil
+Complex('a', exception: false) #: nil
+
+Complex(1, 1) #: Complex
+Complex(1.23, 1.23) #: Complex
+Complex(1r, 1r) #: Complex
+Complex(1i, 1i) #: Complex
+Complex(1ri, 1ri) #: Complex
+Complex(Numeric.new, Numeric.new) #: Complex
+Complex('1+2i', '1+2i') #: Complex
+Complex(2, '1+2i') #: Complex
+
+Complex(1, Raises.new, exception: false) #: nil
+Complex(RaisesNumeric.new, 2, exception: false) #: nil
+Complex('a', 3, exception: false) #: nil
+Complex(2, :untyped, exception: false) #: nil

test/typecheck/complex/test.rbs

@@ -0,0 +1,7 @@
+class Raises
+  def to_c: () -> bot
+end
+
+class RaisesNumeric < Numeric
+  def to_c: () -> bot
+end