[newlib-cygwin] RISC-V: Use newlib nano specific libm.

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=8ef32f2dcfe48b540e64a4ec3ce0dcba5d3b70ce

commit 8ef32f2dcfe48b540e64a4ec3ce0dcba5d3b70ce
Author: Jim Wilson <jimw@sifive.com>
Date:   Wed Jan 29 14:46:17 2020 -0800

    RISC-V: Use newlib nano specific libm.
    
    The libm gamma functions use the _gamma_signgam field of the reentrant
    structure, which changes offset with the --enable-newlib-reent-small
    configure option, which means we need to use a newlib nano specific
    version of libm in addition to libc in the nano.specs file.  Reported
    by Keith Packard.  There is a riscv-gnu-toolchain patch that goes
    along with this to create the new libm_nano.a file.
    
    Signed-off-by: Jim Wilson <jimw@sifive.com>

Diff:
---
 libgloss/riscv/nano.specs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libgloss/riscv/nano.specs b/libgloss/riscv/nano.specs
index 89fd231..e12e313 100644
--- a/libgloss/riscv/nano.specs
+++ b/libgloss/riscv/nano.specs
@@ -15,7 +15,7 @@
 %(nano_link_gcc_c_sequence) --start-group %G %(nano_libc) %(nano_libgloss) --end-group
 
 *link:
-%(nano_link) %:replace-outfile(-lc -lc_nano) %:replace-outfile(-lg -lg_nano)
+%(nano_link) %:replace-outfile(-lc -lc_nano) %:replace-outfile(-lg -lg_nano) %:replace-outfile(-lm -lm_nano)
 
 *lib:
 %{!shared:%{g*:-lg_nano} %{!p:%{!pg:-lc_nano}}%{p:-lc_p}%{pg:-lc_p}}