gnu: samtools: Fix build on i686-linux.

* gnu/packages/bioinformatics.scm (samtools)[arguments]: When building
for i686-linux adjust the make-flags to specifically use the sse math
libraries.

Change-Id: I322d521cbe87e10db7c23db8e68bb377db966aa7

gnu/packages/bioinformatics.scm

@@ -9468,6 +9468,11 @@ to the user's query of interest.")
     (build-system gnu-build-system)
     (arguments
      `(#:configure-flags (list "--with-ncurses")
+       ;; The samtools test suite (and software) expects SSE-based math, even on
+       ;; i686-linux, and not 387-based math.  Adjust the CPPFLAGS accordingly.
+       ,@(if (target-x86-32?)
+             `(#:make-flags (list "CPPFLAGS = -msse -mfpmath=sse"))
+             '())
        #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'patch-tests