internal/task: rename tinygo_pause to tinygo_task_exit

This is more descriptive: the call is to exit a task, not to pause it.
This also makes it more obvious that there's an optimization
opportunity: to free the stack explicitly after the goroutine returns
(or to keep it as a cache for the next stack allocation).

src/internal/task/task_stack.go

@@ -54,8 +54,9 @@ func Pause() {
 	currentTask.state.pause()
 }
 
-//export tinygo_pause
-func pause() {
+//export tinygo_task_exit
+func taskExit() {
+	// TODO: explicitly free the stack after switching back to the scheduler.
 	Pause()
 }
 

src/internal/task/task_stack_386.S

@@ -24,7 +24,7 @@ tinygo_startTask:
     addl $4, %esp
 
     // After return, exit this goroutine. This is a tail call.
-    jmp tinygo_pause
+    jmp tinygo_task_exit
     .cfi_endproc
 
 .global tinygo_swapTask

src/internal/task/task_stack_amd64.S

@@ -30,9 +30,9 @@ tinygo_startTask:
 
     // After return, exit this goroutine. This is a tail call.
     #ifdef __MACH__
-    jmp _tinygo_pause
+    jmp _tinygo_task_exit
     #else
-    jmp tinygo_pause
+    jmp tinygo_task_exit
     #endif
     .cfi_endproc
 

src/internal/task/task_stack_amd64_windows.S

@@ -22,7 +22,7 @@ tinygo_startTask:
 
     // After return, exit this goroutine.
     // This has to be a call, not a jump, to keep the stack correctly aligned.
-    callq tinygo_pause
+    callq tinygo_task_exit
 
 .global tinygo_swapTask
 .section .text.tinygo_swapTask,"ax"

src/internal/task/task_stack_arm.S

@@ -28,7 +28,7 @@ tinygo_startTask:
     blx   r4
 
     // After return, exit this goroutine. This is a tail call.
-    bl    tinygo_pause
+    bl    tinygo_task_exit
     .cfi_endproc
 .size tinygo_startTask, .-tinygo_startTask
 

src/internal/task/task_stack_arm64.S

@@ -27,9 +27,9 @@ tinygo_startTask:
 
     // After return, exit this goroutine. This is a tail call.
 #ifdef __MACH__
-    b     _tinygo_pause
+    b     _tinygo_task_exit
 #else
-    b     tinygo_pause
+    b     tinygo_task_exit
 #endif
     .cfi_endproc
 #ifndef __MACH__

src/internal/task/task_stack_avr.S

@@ -32,10 +32,10 @@ tinygo_startTask:
     // Note that they will probably not be able to run more than the main
     // goroutine anyway, but this file is compiled for all AVRs so it needs to
     // compile at least.
-    rcall  tinygo_pause
+    rcall  tinygo_task_exit
 #else
     // Other devices can (and must) use the regular call instruction.
-    call tinygo_pause
+    call tinygo_task_exit
 #endif
 
 .global tinygo_swapTask

src/internal/task/task_stack_cortexm.S

@@ -28,7 +28,7 @@ tinygo_startTask:
     blx   r4
 
     // After return, exit this goroutine. This is a tail call.
-    bl    	tinygo_pause
+    bl    	tinygo_task_exit
     .cfi_endproc
 .size tinygo_startTask, .-tinygo_startTask
 

src/internal/task/task_stack_esp32.S

@@ -27,7 +27,7 @@ tinygo_startTask:
     callx4 a3
 
     // After return, exit this goroutine. This call never returns.
-    call4  tinygo_pause
+    call4  tinygo_task_exit
 
 .section .text.tinygo_swapTask,"ax",@progbits
 .global tinygo_swapTask

src/internal/task/task_stack_esp8266.S

@@ -18,7 +18,7 @@ tinygo_startTask:
     callx0 a12
 
     // After return, exit this goroutine. This is a tail call.
-    call0  tinygo_pause
+    call0  tinygo_task_exit
 .size tinygo_startTask, .-tinygo_startTask
 
 .global tinygo_swapTask

src/internal/task/task_stack_mipsx.S

@@ -22,7 +22,7 @@ tinygo_startTask:
     nop
 
     // After return, exit this goroutine. This is a tail call.
-    j     tinygo_pause
+    j     tinygo_task_exit
     nop
 
 .section .text.tinygo_swapTask

src/internal/task/task_stack_tinygoriscv.S

@@ -19,7 +19,7 @@ tinygo_startTask:
     jalr  s0
 
     // After return, exit this goroutine. This is a tail call.
-    tail  tinygo_pause
+    tail  tinygo_task_exit
 
 .section .text.tinygo_swapTask
 .global  tinygo_swapTask