Replace core language HexStrings with library entity

[Walter Bright via Digitalmars-d]

BTW, the motivation for x strings is that dumpers often put out results like this:

0000: 80 14  0 12 43 3a 5c 63 62 78 5c 6d 61 72 73 5c    ....C:\cbx\mars\
0010: 74 6f 69 72 2e 63  0 88  6  0  0 9d 37 6e 4f  0    toir.c......7nO.
0020: 88  6  0  0 a1  1 43 56  0 96 4c  0  0  4 46 4c    ......CV..L...FL
0030: 41 54  5 5f 54 45 58 54  4 43 4f 44 45  5 5f 44    AT._TEXT.CODE._D
0040: 41 54 41  4 44 41 54 41  5 43 4f 4e 53 54  4 5f    ATA.DATA.CONST._
0050: 42 53 53  3 42 53 53  7 24 24 54 59 50 45 53  6    BSS.BSS.$$TYPES.
0060: 44 45 42 54 59 50  9 24 24 53 59 4d 42 4f 4c 53    DEBTYP.$$SYMBOLS
0070:  6 44 45 42 53 59 4d  0 99  9  0 a9 d7 11  0  0    .DEBSYM.........
0080:  3  4  1  0 99  9  0 a9 78 10  0  0  5  6  1  0    ........x.......
0090: 99  9  0 a9  0  0  0  0  7  7  1  0 99  9  0 a9    ................
00a0:  0  0  0  0  8  9  1  0 99  9  0 a1 15  e  0  0    ................
00b0:  c  d  1  0 99  9  0 a1 e3 39  0  0  a  b  1  0    .........9......
00c0: 9a  2  0  2  0 91 73  0  0  1 2e 3f 69 6e 63 55    ......s....?incU
00d0: 73 61 67 65 45 6c 65 6d 40 40 59 41 50 41 55 65    sageElem@@YAPAUe
00e0: 6c 65 6d 40 40 50 41 55 49 52 53 74 61 74 65 40    lem@@PAUIRState@
00f0: 40 55 4c 6f 63 40 40 40 5a 10  0  0  0  0 36 3f    @ULoc@@@Z.....6?
0100: 67 65 74 45 74 68 69 73 40 40 59 41 50 41 55 65    getEthis@@YAPAUe
0110: 6c 65 6d 40 40 55 4c 6f 63 40 40 50 41 55 49 52    lem@@ULoc@@PAUIR
0120: 53 74 61 74 65 40 40 50 41 56 44 73 79 6d 62 6f    State@@PAVDsymbo
0130: 6c 40 40 40 5a  7  1  0  0  0  0 95  1  2  0  1    l@@@Z...........

and it's a giant pain to add all the \x notations, besides making it unreadably 
ugly.