feat: convert fiber tests to use block arguments instead of anonymous function literals

Update all fiber test files to replace `Fiber.create(fn { ... })` with `Fiber.create { ... }` block syntax, and add compiler support for parsing block bodies without requiring a newline after the opening brace. The compiler changes include removing `TOKEN_LEFT_BRACE` from the newline-discarding token list and adding `match(compiler, TOKEN_LINE)` calls in `finishBlock`, `methodCall`, `function`, and `block` to handle empty block bodies and inline expressions.

test/fiber/is_done.wren

@@ -1,8 +1,8 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("1")
   Fiber.yield
   IO.print("2")
-})
+}
 
 IO.print(fiber.isDone)  // expect: false
 fiber.run               // expect: 1

test/fiber/resume_caller.wren

@@ -1,12 +1,12 @@
-var b = Fiber.create(fn {
+var b = Fiber.create {
   IO.print("fiber b")
-})
+}
 
-var a = Fiber.create(fn {
+var a = Fiber.create {
   IO.print("begin fiber a")
   b.run
   IO.print("end fiber a")
-})
+}
 
 IO.print("begin main")
 a.run

test/fiber/run.wren

@@ -1,6 +1,6 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber")
-})
+}
 
 IO.print("before") // expect: before
 fiber.run          // expect: fiber

test/fiber/run_return_implicit_null.wren

@@ -1,6 +1,6 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber")
-})
+}
 
 var result = fiber.run // expect: fiber
 IO.print(result)       // expect: null

test/fiber/run_return_value.wren

@@ -1,7 +1,7 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber")
   return "result"
-})
+}
 
 var result = fiber.run // expect: fiber
 IO.print(result)       // expect: result

test/fiber/run_when_done.wren

@@ -1,6 +1,6 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("run")
-})
+}
 
 fiber.run // expect: run
 fiber.run // expect runtime error: Cannot run a finished fiber.

test/fiber/run_with_value.wren

@@ -1,6 +1,6 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber")
-})
+}
 
 // The first value passed to the fiber is ignored, since there's no yield call
 // to return it.

test/fiber/run_with_value_when_done.wren

@@ -1,6 +1,6 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("run")
-})
+}
 
 fiber.run(1) // expect: run
 fiber.run(2) // expect runtime error: Cannot run a finished fiber.

test/fiber/type.wren

@@ -1,4 +1,4 @@
-var fiber = Fiber.create(fn null)
+var fiber = Fiber.create {}
 IO.print(fiber is Fiber)      // expect: true
 IO.print(fiber is Object)     // expect: true
 IO.print(fiber is Bool)       // expect: false

test/fiber/yield.wren

@@ -1,10 +1,10 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber 1")
   Fiber.yield
   IO.print("fiber 2")
   Fiber.yield
   IO.print("fiber 3")
-})
+}
 
 var result = fiber.run // expect: fiber 1
 IO.print("main 1") // expect: main 1

test/fiber/yield_return_value.wren

@@ -1,10 +1,10 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber 1")
   var result = Fiber.yield
   IO.print(result)
   result = Fiber.yield
   IO.print(result)
-})
+}
 
 fiber.run // expect: fiber 1
 IO.print("main 1") // expect: main 1

test/fiber/yield_with_value.wren

@@ -1,10 +1,10 @@
-var fiber = Fiber.create(fn {
+var fiber = Fiber.create {
   IO.print("fiber 1")
   Fiber.yield("yield 1")
   IO.print("fiber 2")
   Fiber.yield("yield 2")
   IO.print("fiber 3")
-})
+}
 
 var result = fiber.run // expect: fiber 1
 IO.print(result) // expect: yield 1