Turn enum : char into enum : signed char if it contains negative values

src/engraving/libmscore/textbase.h

@@ -46,7 +46,7 @@ enum class FrameType : char {
 //   VerticalAlignment
 //---------------------------------------------------------
 
-enum class VerticalAlignment : char {
+enum class VerticalAlignment : signed char {
     AlignUndefined = -1, AlignNormal, AlignSuperScript, AlignSubScript
 };
 

src/engraving/libmscore/types.h

@@ -470,7 +470,7 @@ constexpr bool operator&(const SegmentType t1, const SegmentType t2)
 //   FontStyle
 //---------------------------------------------------------
 
-enum class FontStyle : char {
+enum class FontStyle : signed char {
     Undefined = -1,
     Normal = 0,
     Bold = 1 << 0,

src/engraving/types/types.h

@@ -409,7 +409,7 @@ enum class HookType : char {
 };
 
 // P_TYPE::KEY_MODE
-enum class KeyMode : char {
+enum class KeyMode : signed char {
     UNKNOWN = -1,
     NONE,
     MAJOR,