Minor, fix double-promotion warnings (#1221)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6b63f1a..af443ad 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -91,7 +91,7 @@
       - run: apt update || true
       - run: apt install -y clang lld binutils libtool autoconf automake make pkg-config gtk-doc-tools ragel libfreetype6-dev libfontconfig1-dev libglib2.0-dev libcairo2-dev libicu-dev libgraphite2-dev python python-pip
       - run: pip install fonttools
-      - run: CFLAGS="-Weverything -Wno-reserved-id-macro -Wno-conversion -Wno-padded -Wno-sign-conversion -Wno-cast-qual -Wno-documentation -Wno-documentation-unknown-command" CXXFLAGS="-Weverything -Wno-old-style-cast -Wno-documentation -Wno-documentation-unknown-command -Wno-c++98-compat -Wno-cast-qual -Wno-c++98-compat-pedantic -Wno-sign-conversion -Wno-padded -Wno-shorten-64-to-32 -Wno-extra-semi -Wno-reserved-id-macro -Wno-float-conversion -Wno-format-pedantic -Wno-shadow -Wno-conversion -Wno-zero-as-null-pointer-constant -Wno-missing-field-initializers -Wno-double-promotion -Wno-used-but-marked-unused -Wno-unused-macros -Wno-comma -Wno-float-equal -Wno-disabled-macro-expansion -Wno-weak-vtables -Wno-unused-parameter -Wno-covered-switch-default -Wno-unreachable-code" CC=clang CXX=clang++ ./autogen.sh --with-freetype --with-glib --with-cairo --with-icu --with-graphite2 --with-fontconfig
+      - run: CFLAGS="-Weverything -Wno-reserved-id-macro -Wno-conversion -Wno-padded -Wno-sign-conversion -Wno-cast-qual -Wno-documentation -Wno-documentation-unknown-command" CXXFLAGS="-Weverything -Wno-old-style-cast -Wno-documentation -Wno-documentation-unknown-command -Wno-c++98-compat -Wno-cast-qual -Wno-c++98-compat-pedantic -Wno-sign-conversion -Wno-padded -Wno-shorten-64-to-32 -Wno-extra-semi -Wno-reserved-id-macro -Wno-float-conversion -Wno-format-pedantic -Wno-shadow -Wno-conversion -Wno-zero-as-null-pointer-constant -Wno-missing-field-initializers -Wno-used-but-marked-unused -Wno-unused-macros -Wno-comma -Wno-float-equal -Wno-disabled-macro-expansion -Wno-weak-vtables -Wno-unused-parameter -Wno-covered-switch-default -Wno-unreachable-code" CC=clang CXX=clang++ ./autogen.sh --with-freetype --with-glib --with-cairo --with-icu --with-graphite2 --with-fontconfig
       - run: make -j32 CPPFLAGS="-Werror"
       - run: make check CPPFLAGS="-Werror" || .ci/fail.sh
 
diff --git a/src/dump-emoji.cc b/src/dump-emoji.cc
index 3e0d668..b5ec30e 100644
--- a/src/dump-emoji.cc
+++ b/src/dump-emoji.cc
@@ -146,7 +146,7 @@
 	  int r = (color >> 8) & 0xFF;
 	  int g = (color >> 16) & 0xFF;
 	  int b = (color >> 24) & 0xFF;
-	  cairo_set_source_rgba (cr, r / 255.f, g / 255.f, b / 255.f, alpha);
+	  cairo_set_source_rgba (cr, r / 255., g / 255., b / 255., alpha);
 
 	  cairo_glyph_t glyph;
 	  glyph.index = glyph_id;
diff --git a/src/hb-common.cc b/src/hb-common.cc
index 16f8701..41b1601 100644
--- a/src/hb-common.cc
+++ b/src/hb-common.cc
@@ -1072,7 +1072,7 @@
   while (len && s[len - 1] == ' ')
     len--;
   s[len++] = '=';
-  len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%g", variation->value));
+  len += MAX (0, snprintf (s + len, ARRAY_LENGTH (s) - len, "%g", (double) variation->value));
 
   assert (len < ARRAY_LENGTH (s));
   len = MIN (len, size - 1);
diff --git a/src/hb-ot-var-fvar-table.hh b/src/hb-ot-var-fvar-table.hh
index 1d17a97..96c39c1 100644
--- a/src/hb-ot-var-fvar-table.hh
+++ b/src/hb-ot-var-fvar-table.hh
@@ -177,7 +177,7 @@
       v = (v - axis.default_value) / (axis.default_value - axis.min_value);
     else
       v = (v - axis.default_value) / (axis.max_value - axis.default_value);
-    return (int) (v * 16384. + (v >= 0. ? .5 : -.5));
+    return (int) (v * 16384.f + (v >= 0.f ? .5f : -.5f));
   }
 
   protected: