seems strange. On my systems (Linux and OpenBSD) neither perl nor gcc has no need in libglib.

fisher@ws% ldd `which perl`
        linux-vdso.so.1 =>  (0x00007fff527ff000)
        libperl.so.5.10 => /usr/lib/libperl.so.5.10 (0x00007f1e76cbc00
+0)
        libdl.so.2 => /lib/libdl.so.2 (0x00007f1e76ab8000)
        libm.so.6 => /lib/libm.so.6 (0x00007f1e76835000)
        libpthread.so.0 => /lib/libpthread.so.0 (0x00007f1e76619000)
        libc.so.6 => /lib/libc.so.6 (0x00007f1e762b8000)
        libcrypt.so.1 => /lib/libcrypt.so.1 (0x00007f1e76080000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f1e7704c000)
fisher@ws% ldd `which gcc` 
        linux-vdso.so.1 =>  (0x00007fffe37ff000)
        libc.so.6 => /lib/libc.so.6 (0x00007f5675958000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f5675cdc000)
fisher@ws%
[download]

openbook% ldd `which perl`
/usr/bin/perl:
        Start    End      Type Open Ref GrpRef Name
        1c000000 3c004000 exe  1    0   0      /usr/bin/perl
        02a25000 22a45000 rlib 0    1   0      /usr/lib/libperl.so.11.
+1
        0fd26000 2fd30000 rlib 0    1   0      /usr/lib/libm.so.5.2
        0cb04000 2cb08000 rlib 0    1   0      /usr/lib/libutil.so.11.
+0
        0ad8d000 2adc6000 rlib 0    1   0      /usr/lib/libc.so.53.1
        012eb000 012eb000 rtld 0    1   0      /usr/libexec/ld.so
openbook% ldd `which gcc` 
/usr/bin/gcc:
        Start    End      Type Open Ref GrpRef Name
        1c000000 3c008000 exe  1    0   0      /usr/bin/gcc
        0df9c000 2dfa3000 rlib 0    1   0      /usr/lib/libiberty.so.1
+0.0
        02cb1000 22cea000 rlib 0    1   0      /usr/lib/libc.so.53.1
        087bd000 087bd000 rtld 0    1   0      /usr/libexec/ld.so
openbook%
[download]

Are you sure you talking about core system and not the perl module Glib, for example?