[Tolk] Tolk v0.5.0 as FunC v0.5.0 could have been like

All changes from PR "FunC v0.5.0":
https://github.com/ton-blockchain/ton/pull/1026

Instead of developing FunC, we decided to fork it.
BTW, the first Tolk release will be v0.6,
a metaphor of FunC v0.5 that missed a chance to occur.

crypto/smartcont/mathlib.tolk

@@ -81,14 +81,14 @@ int fixed248::acot(int x) inline_ref;
 
 ;; random number uniformly distributed in [0..1)
 ;; fixed248 random();
-int fixed248::random() impure inline;
+int fixed248::random() inline;
 ;; random number with standard normal distribution (2100 gas on average)
 ;; fixed248 nrand();
-int fixed248::nrand() impure inline;
+int fixed248::nrand() inline;
 ;; generates a random number approximately distributed according to the standard normal distribution (1200 gas)
 ;; (fails chi-squared test, but it is shorter and faster than fixed248::nrand())
 ;; fixed248 nrand_fast();
-int fixed248::nrand_fast() impure inline;
+int fixed248::nrand_fast() inline;
 
 -}  ;; end (declarations)
 
@@ -880,7 +880,7 @@ int fixed248::acot(int x) inline_ref {
 ;; generated by Kinderman--Monahan ratio method modified by J.Leva
 ;; spends ~ 2k..3k gas on average
 ;; fixed252 nrand();
-int nrand_f252() impure inline_ref {
+int nrand_f252() inline_ref {
   var (x, s, t, A, B, r0) = (nan(), touch(29483) << 236, touch(-3167) << 239, 12845, 16693, 9043);
   ;; 4/sqrt(e*Pi) = 1.369 loop iterations on average
   do {
@@ -910,7 +910,7 @@ int nrand_f252() impure inline_ref {
 ;; generates a random number approximately distributed according to the standard normal distribution
 ;; much faster than nrand_f252(), should be suitable for most purposes when only several random numbers are needed
 ;; fixed252 nrand_fast();
-int nrand_fast_f252() impure inline_ref {
+int nrand_fast_f252() inline_ref {
   int t = touch(-3) << 253;   ;; -6. as fixed252
   repeat (12) {
     t += random() / 16;         ;; add together 12 uniformly random numbers
@@ -920,18 +920,18 @@ int nrand_fast_f252() impure inline_ref {
 
 ;; random number uniformly distributed in [0..1)
 ;; fixed248 random();
-int fixed248::random() impure inline {
+int fixed248::random() inline {
   return random() >> 8;
 }
 
 ;; random number with standard normal distribution
 ;; fixed248 nrand();
-int fixed248::nrand() impure inline {
+int fixed248::nrand() inline {
   return nrand_f252() ~>> 4;
 }
 
 ;; generates a random number approximately distributed according to the standard normal distribution
 ;; fixed248 nrand_fast();
-int fixed248::nrand_fast() impure inline {
+int fixed248::nrand_fast() inline {
   return nrand_fast_f252() ~>> 4;
 }