- Use %license (boo#1082318)

- Add systemtap-headers to BuildRequires
- Add --enable-systemtap to configure arguments (fate#324969, bsc#1073636)

- riscv-readelflib.patch: Fix parsing flags in ELF64 files on riscv

- Update to glibc 2.27
* Optimized x86-64 asin, atan2, exp, expf, log, pow, atan, sin, cosf,
sinf, sincosf and tan with FMA
* Optimized x86-64 trunc and truncf for processors with SSE4.1
* Optimized generic expf, exp2f, logf, log2f, powf, sinf, cosf and
sincosf
* In order to support faster and safer process termination the malloc API
family of functions will no longer print a failure address and stack
backtrace after detecting heap corruption
* The abort function terminates the process immediately, without flushing
stdio streams
* On platforms where long double has the IEEE binary128 format (aarch64,
alpha, mips64, riscv, s390 and sparc), the math library now implements
_Float128 interfaces for that type, as defined by ISO/IEC TS 18661-3:2015
These are the same interfaces added in version 2.26 for some platforms where
this format is supported but is not the format of long double
* On platforms with support for _Float64x (aarch64, alpha, i386, ia64,
mips64, powerpc64le, riscv, s390, sparc and x86_64), the math library now
implements interfaces for that type, as defined by ISO/IEC TS
18661-3:2015
* The math library now implements interfaces for the _Float32, _Float64 and
_Float32x types, as defined by ISO/IEC TS 18661-3:2015
* glibc now implements the memfd_create and mlock2 functions on Linux