restrict dispatch of some custrom string macros to String (#57781)

Restricts the dispatch for these macros so that only `String` (literal)
arguments are accepted:
* `int128_str`
* `uint128_str`
* `big_str`
* `ip_str` from the Sockets stdlib
* `dateformat_str` from the Dates stdlib

Some of these changes make the code in the sysimage less vulnerable to
invalidation.

(cherry picked from commit f9365a5)

Author: nsajko

base/int.jl

@@ -711,7 +711,7 @@ ERROR: LoadError: ArgumentError: invalid base 10 digit '.' in "123456789123.4"
 [...]
 ```
 """
-macro int128_str(s)
+macro int128_str(s::String)
     return parse(Int128, s)
 end
 
@@ -731,7 +731,7 @@ ERROR: LoadError: ArgumentError: invalid base 10 digit '-' in "-123456789123"
 [...]
 ```
 """
-macro uint128_str(s)
+macro uint128_str(s::String)
     return parse(UInt128, s)
 end
 
@@ -755,7 +755,7 @@ ERROR: ArgumentError: invalid number format _ for BigInt or BigFloat
 [...]
 ```
 """
-macro big_str(s)
+macro big_str(s::String)
     message = "invalid number format $s for BigInt or BigFloat"
     throw_error =  :(throw(ArgumentError($message)))
     if '_' in s

stdlib/Dates/src/io.jl

@@ -460,7 +460,7 @@ but creates the DateFormat object once during macro expansion.
 
 See [`DateFormat`](@ref) for details about format specifiers.
 """
-macro dateformat_str(str)
+macro dateformat_str(str::String)
     DateFormat(str)
 end
 

stdlib/Sockets/src/IPAddr.jl

@@ -265,7 +265,7 @@ julia> @ip_str "2001:db8:0:0:0:0:2:1"
 ip"2001:db8::2:1"
 ```
 """
-macro ip_str(str)
+macro ip_str(str::String)
     return parse(IPAddr, str)
 end