improvements to addInt and $ for integer types (#18592)

* improvements to $(SomeInteger) and addInt
* remove mIntToStr, mInt64ToStr
* improvements
* fix tests/pragmas/tinjectstmt.nim; the diff is harmless, cgen code is identical with -d:danger or debug mode
* rm tests/system/tstrmantle.nim
* revert compiler/jsgen.nim for -d:nimVersion140

tests/pragmas/tinjectstmt.nim

@@ -7,15 +7,18 @@ ok0
 ok1
 onInject: 3
 onInject: 4
-0
 onInject: 5
+0
 onInject: 6
-1
 onInject: 7
 onInject: 8
+1
+onInject: 9
+onInject: 10
+onInject: 11
 2
 ok2
-onInject: 9
+onInject: 12
 '''
 """
 
@@ -25,7 +28,7 @@ onInject: 9
 {.injectStmt.} pragma can be used to inject a statement before every
 other statement in the current module. It's now undocumented and may be removed
 in the future and replaced with something more general and without its limitations.
-e.g. (e.g. doesn't work in VM or js backends).
+(e.g. doesn't work in VM or js backends).
 ]#
 
 from system/ansi_c import c_printf
@@ -44,5 +47,5 @@ proc main()=
     echo a
   echo "ok2"
 
-static: main() # xxx injectStmt not honred in VM
+static: main() # xxx injectStmt not honored in VM
 main()

tests/system/tdollars.nim

@@ -102,40 +102,41 @@ block: # #14350, #16674, #16686 for JS
     doAssert nil2 == cstring("")
 
 block:
-  block:
-    let x = -1'i8
-    let y = uint32(x)
-
-    doAssert $y == "4294967295"
-
-  block:
-    let x = -1'i16
-    let y = uint32(x)
-
-    doAssert $y == "4294967295"
-
-  block:
-    let x = -1'i32
-    let y = uint32(x)
-
-    doAssert $y == "4294967295"
+  when defined(js): # bug #18591
+    let a1 = -1'i8
+    let a2 = uint8(a1)
+    # if `uint8(a1)` changes meaning to `cast[uint8](a1)` in future, update this test;
+    # until then, this is the correct semantics.
+    let a3 = $a2
+    doAssert a2 < 3
+    doAssert a3 == "-1"
+    proc intToStr(a: uint8): cstring {.importjs: "(# + \"\")".}
+    doAssert $intToStr(a2) == "-1"
+  else:
+    block:
+      let x = -1'i8
+      let y = uint32(x)
+      doAssert $y == "4294967295"
+    block:
+      let x = -1'i16
+      let y = uint32(x)
+      doAssert $y == "4294967295"
+    block:
+      let x = -1'i32
+      let y = uint32(x)
+      doAssert $y == "4294967295"
+    block:
+      proc foo1(arg: int): string =
+        let x = uint32(arg)
+        $x
+      doAssert $foo1(-1) == "4294967295"
 
   block:
     let x = 4294967295'u32
     doAssert $x == "4294967295"
-
   block:
     doAssert $(4294967295'u32) == "4294967295"
 
-
-  block:
-    proc foo1(arg: int): string =
-      let x = uint32(arg)
-      $x
-
-    doAssert $foo1(-1) == "4294967295"
-
-
 proc main()=
   block:
     let a = -0.0
@@ -159,6 +160,32 @@ proc main()=
 
   doAssert $uint32.high == "4294967295"
 
+  block: # addInt
+    var res = newStringOfCap(24)
+    template test2(a, b) =
+      res.setLen(0)
+      res.addInt a
+      doAssert res == b
+
+    for i in 0 .. 9:
+      res.addInt int64(i)
+    doAssert res == "0123456789"
+
+    res.setLen(0)
+    for i in -9 .. 0:
+      res.addInt int64(i)
+    doAssert res == "-9-8-7-6-5-4-3-2-10"
+
+    when not defined(js):
+      test2 high(int64), "9223372036854775807"
+      test2 low(int64), "-9223372036854775808"
+
+    test2 high(int32), "2147483647"
+    test2 low(int32), "-2147483648"
+    test2 high(int16), "32767"
+    test2 low(int16), "-32768"
+    test2 high(int8), "127"
+    test2 low(int8), "-128"
 
 static: main()
 main()

tests/system/tstrmantle.nim

@@ -1,46 +0,0 @@
-var res = newStringOfCap(24)
-
-for i in 0 .. 9:
-  res.addInt int64(i)
-
-doAssert res == "0123456789"
-
-res.setLen(0)
-
-for i in -9 .. 0:
-  res.addInt int64(i)
-
-doAssert res == "-9-8-7-6-5-4-3-2-10"
-
-res.setLen(0)
-res.addInt high(int64)
-doAssert res == "9223372036854775807"
-
-res.setLen(0)
-res.addInt low(int64)
-doAssert res == "-9223372036854775808"
-
-res.setLen(0)
-res.addInt high(int32)
-doAssert res == "2147483647"
-
-res.setLen(0)
-res.addInt low(int32)
-doAssert res == "-2147483648"
-
-res.setLen(0)
-res.addInt high(int16)
-doAssert res == "32767"
-
-res.setLen(0)
-res.addInt low(int16)
-doAssert res == "-32768"
-
-
-res.setLen(0)
-res.addInt high(int8)
-doAssert res == "127"
-
-res.setLen(0)
-res.addInt low(int8)
-doAssert res == "-128"