Add semantic check for precision qualifier on wrong kind of type. Added a few more tests.

Test/120.frag

@@ -78,7 +78,23 @@ void main()
         bool b;
         gl_FragColor += b ? v : m;  // ERROR, types don't match around ":"
     }
+
+    gl_FragColor.xr;    // ERROR, swizzlers not from same field space
+    centTexCoord.z;     // ERROR, swizzler out of range
+    (a,b) = true;       // ERROR, not an l-value
 }
 
 float imageBuffer;
 float uimage2DRect;
+
+int main() {}           // ERROR
+void main(int a) {}     // ERROR
+
+const int a;            // ERROR
+
+int foo(in float a);
+int foo(out float a)    // ERROR
+{
+    return 3.2;         // ERROR
+    foo(a);             // ERROR
+}

Test/array.frag

@@ -54,4 +54,6 @@ void main()
     const int ca3[3] = int[](3, 2);  // ERROR
     int ica[] = int[](3, 2);
     int ica3[3] = int[](3, 2);       // ERROR
+    ica[3.1] = 3;                    // ERROR
+    ica[u[1]] = 4;                   // ERROR
 }

Test/precision.frag

@@ -68,3 +68,9 @@ void main()
     texture2D(samplerMed, vec2(0.1, 0.2));
     texture2D(samplerHigh, vec2(0.1, 0.2));
 }
+
+precision mediump bool;                 // ERROR
+//precision mediump struct { int a; } s;  // ERROR
+struct s {int a;};
+precision mediump s;                    // ERROR
+mediump bvec2 b2;                       // ERROR

glslang/MachineIndependent/ParseHelper.cpp

@@ -891,7 +891,8 @@ void TParseContext::precisionQualifierCheck(int line, TPublicType& publicType)
     if (publicType.basicType == EbtFloat || publicType.basicType == EbtUint || publicType.basicType == EbtInt || publicType.basicType == EbtSampler) {
         if (publicType.qualifier.precision == EpqNone)
             error(line, "type requires declaration of default precision qualifier", TType::getBasicString(publicType.basicType), "");
-    }
+    } else if (publicType.qualifier.precision != EpqNone)
+        error(line, "type cannot have precision qualifier", TType::getBasicString(publicType.basicType), "");
 }
 
 void TParseContext::parameterSamplerCheck(int line, TStorageQualifier qualifier, const TType& type)