Deprecate 'c', 'C' prefix for octal literals, fixes #8082 (#8178)

* deprecate `0c`, `0C` prefix for octal literals

Deprecates the previously allowed syntax of `0c` and `0C` as a prefix for
octal literals to bring the literals in line with the behavior of
`parseOct` from parseutils.

* add `msgKind` arg to `lexMessageLitNum` for deprecation messages

* change literal tests to check all valid integer literals

Also adds the `tinvaligintegerlit3` test to test for the (still)
invalid `0O` prefix.

tests/lexer/tintegerliterals.nim

@@ -0,0 +1,9 @@
+# test the valid literals
+assert 0b10 == 2
+assert 0B10 == 2
+assert 0x10 == 16
+assert 0X10 == 16
+assert 0o10 == 8
+# the following is deprecated:
+assert 0c10 == 8
+assert 0C10 == 8

tests/lexer/tinvalidintegerliteral3.nim

@@ -0,0 +1,7 @@
+discard """
+  file: "tinvalidintegerliteral3.nim"
+  line: 7
+  errormsg: "0O5 is an invalid int literal; For octal literals use the '0o' prefix."
+"""
+
+echo 0O5

tests/misc/tunsignedmisc.nim

@@ -9,7 +9,7 @@ discard """
 # 8 bit
 let ref1 = 128'u8 shr 7
 let hex1 = 0x80'u8 shr 7
-let oct1 = 0c200'u8 shr 7
+let oct1 = 0o200'u8 shr 7
 let dig1 = 0b10000000'u8 shr 7
 
 doAssert(ref1 == 1)
@@ -20,7 +20,7 @@ doAssert(ref1 == dig1)
 # 16 bit
 let ref2 = 32768'u16 shr 15
 let hex2 = 0x8000'u16 shr 15
-let oct2 = 0c100000'u16 shr 15
+let oct2 = 0o100000'u16 shr 15
 let dig2 = 0b1000000000000000'u16 shr 15
 
 doAssert(ref2 == 1)
@@ -31,7 +31,7 @@ doAssert(ref2 == dig2)
 # 32 bit
 let ref3 = 2147483648'u32 shr 31
 let hex3 = 0x80000000'u32 shr 31
-let oct3 = 0c20000000000'u32 shr 31
+let oct3 = 0o20000000000'u32 shr 31
 let dig3 = 0b10000000000000000000000000000000'u32 shr 31
 
 doAssert(ref3 == 1)