Factor our `FP_CAPITALIZE_YES_NO`

This deduplicates converting from yes/no to YES/NO in the configure
scripts while also making it safer.

m4/fp_capitalize_yes_no.m4

+# FP_CAPITALIZE_YES_NO(scrutinee, out_var)
+# ---------------------------------------------------
+# Helper for converting a yes/no to a YES/NO.
+#
+# $1 = shell expression evaluating to yes/no.
+# $2 = name of variable to set wit YES/NO.
+AC_DEFUN([FP_CAPITALIZE_YES_NO],
+[AS_CASE(
+    [x$1],
+    [x"yes"], [$2=YES],
+    [x"no"], [$2=NO],
+    [AC_MSG_ERROR([invalid value:] $1 [is not "yes" or "no"])])
+])

m4/fp_gmp.m4

@@ -19,13 +19,13 @@ AC_DEFUN([FP_GMP],
   AC_ARG_WITH([intree-gmp],
     [AS_HELP_STRING([--with-intree-gmp],
       [force using the in-tree GMP])],
-      [GMP_FORCE_INTREE=YES],
+      [FP_CAPITALIZE_YES_NO(["$withval"], [GMP_FORCE_INTREE])],
       [GMP_FORCE_INTREE=NO])
 
   AC_ARG_WITH([gmp-framework-preferred],
     [AS_HELP_STRING([--with-gmp-framework-preferred],
       [on OSX, prefer the GMP framework to the gmp lib])],
-      [GMP_PREFER_FRAMEWORK=YES],
+      [FP_CAPITALIZE_YES_NO(["$withval"], [GMP_PREFER_FRAMEWORK])],
       [GMP_PREFER_FRAMEWORK=NO])
 
   AC_SUBST(GMP_INCLUDE_DIRS)

m4/fp_prog_ld_build_id.m4

@@ -13,11 +13,7 @@ else
    fp_cv_ld_build_id=no
 fi
 rm -rf conftest*])
-if test "$fp_cv_ld_build_id" = yes; then
-  LdHasBuildId=YES
-else
-  LdHasBuildId=NO
-fi
+FP_CAPITALIZE_YES_NO(["$fp_cv_ld_build_id"], [LdHasBuildId])
 AC_SUBST([LdHasBuildId])
 ])# FP_PROG_LD_BUILD_ID
 

m4/fp_prog_ld_filelist.m4

@@ -20,10 +20,6 @@ AC_CACHE_CHECK([whether ld understands -filelist], [fp_cv_ld_has_filelist],
     fi
     rm -rf conftest*
 ])
-if test "$fp_cv_ld_has_filelist" = yes; then
-    LdHasFilelist=YES
-else
-    LdHasFilelist=NO
-fi
+FP_CAPITALIZE_YES_NO(["$fp_cv_ld_has_filelist"], [LdHasFilelist])
 AC_SUBST([LdHasFilelist])
 ])# FP_PROG_LD_FILELIST

m4/fp_prog_ld_no_compact_unwind.m4

@@ -13,10 +13,6 @@ else
    fp_cv_ld_no_compact_unwind=no
 fi
 rm -rf conftest*])
-if test "$fp_cv_ld_no_compact_unwind" = yes; then
-  LdHasNoCompactUnwind=YES
-else
-  LdHasNoCompactUnwind=NO
-fi
+FP_CAPITALIZE_YES_NO(["$fp_cv_ld_no_compact_unwind"], [LdHasNoCompactUnwind])
 AC_SUBST([LdHasNoCompactUnwind])
 ])# FP_PROG_LD_NO_COMPACT_UNWIND